39365093-AP-Bio-Test-Questions

39365093-AP-Bio-Test-Questions - What is the reducing agent...

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Unformatted text preview: What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. NADH Correct Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. e. monomers Correct When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? Choose one answer. c. the cell will become turgid Correct When pairs of homologous chromosomes separate during anaphase I, Choose one answer. a. the sister chromatids remain attached to one another. Correct Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt × BBtt will have black fur and long tails? Choose one answer. d. 1/2 Correct Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. d. No groups have such higher frequency Correct The body is capable of catabolizing many substances as sources of energy. Which of the followingwould be used as an energy source only after the depletion of other sources? Choose one answer. d. protein in muscle cells Correct Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that Choose one answer. c. None of the other answer choices correctly describes these solutions. Correct A gene's location along a chromosome is known as which of the following? Choose one answer. a. Locus Correct Which of the following is a nutritional monomer that can be transported in the blood? Choose one answer. b. fatty acid Correct Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. e. kidneys of vertebrates Correct Which of these stimulate the production of red blood cells? Choose one answer. d. erythropoietin Correct In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. b. proteins and nucleic acids. Correct Independent assortment of chromosomes is a result of Choose one answer. a. the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. Correct Which of the following is an example of countercurrent exchange? Choose one answer. d. the flow of water across the gills of a fish and that of blood within those gills Correct SRY is best described in which of the following ways? Choose one answer. c. A gene region present on the Y chromosome that triggers male development Correct Which of the following is an example of qualitative data? Choose one answer. e. The fish swam in a zig-zag motion. Correct What does a frequency of recombination of 50% indicate? Choose one answer. e. The two genes are likely to be located on different chromosomes. Correct You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample? Choose one answer. a. 6.02 × 1024 Correct Which of the following span the phospholipids bilayer, usually a number of times? Choose one answer. a. transmembrane proteins Correct Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct Individuals whose diet consists primarily of corn would likely become Choose one answer. d. malnourished. Correct Which of the following is true for all exergonic reactions? Choose one answer. b. The reactions are nonspontaneous. Incorrect Where are the molecules of the electron transport chain found in plant cells? Choose one answer. b. thylakoid membranes of chloroplasts Correct DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run? Choose one answer. e. None of the individual insects should have possessed genomes that made them resistant to DDT. Correct Choose one answer. d. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct An organism has a relatively large number of Hox genes in its genome. Which of the following is not true of this organism? Choose one answer. b. It must have multiple paired appendages along the length of its body. Correct A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. blue and violet Correct Birds secrete uric acid as their nitrogenous waste because uric acid Choose one answer b. requires little water for nitrogenous waste disposal which is conducive to the function of flight in terms of weight. Correct When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, -S Correct This is the shortest part of the cell cycle: Choose one answer. b. M Correct Which of the following takes place as an ice cube cools a drink? Choose one answer. a. Kinetic energy in the drink decreases. Correct What was the prevailing notion prior to the time of Lyell and Darwin? Choose one answer. b. Earth is a few thousand years old, and populations are unchanging. Correct Which of the following is not a theme that unifies biology? Choose one answer. c. reductionism Correct Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants Choose one answer. e. a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. Correct Which of the following is present in a prokaryotic cell? Choose one answer. d. ribosome Correct All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. c. Characteristics of organisms are inherited as genes on chromosomes. Correct The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via which of the following? Choose one answer. e. integrins Correct Which of these naturalists synthesized a concept of natural selection independently of Darwin? Choose one answer. c. Alfred Wallace Correct Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur? Choose one answer. b. in photosynthesizing cells in dark periods and in other tissues all the time Correct Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited? Choose one answer. b. Nervous and muscular systems Correct Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. c. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct In which of the following would there be the greatest need for osmoregulation? Choose one answer. e. a terrestrial animal such as a snake Correct Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. b. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct Which of the following enzymes works most effectively at a very low pH? Choose one answer. c. pepsin Correct What is the main nitrogenous waste excreted by birds? Choose one answer. c. uric acid Correct Which of these is a statement that Darwin would have rejected? Choose one answer. d. The smallest entity that can evolve is an individual organism. Correct During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. c. FADH2 Correct Where and from what compound(s) is urea produced? Choose one answer. c. liver from NH3 and CO2 Correct Large proteins such as albumin remain in capillaries rather than diffusing out. Which of the following does this cause? Choose one answer. a. creation of an osmotic pressure difference across capillary walls Correct The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. neither photosynthesis nor respiration. Correct Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be Choose one answer. b. to test for liberation of O2 in the light. Correct Life is diverse. How many species are estimated to be presently on the earth? Choose one answer. d. 1,800,000 Correct A molecule that is phosphorylated Choose one answer. c. has an increased chemical reactivity; it is primed to do cellular work. Correct What does the chemiosmotic process in chloroplasts involve? Choose one answer. a. establishment of a proton gradient Correct Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? Choose one answer. a. compartmentalization of enzymes into defined organelles Correct A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis? Choose one answer. b. The animal has a very long distance between heart and brain. Correct For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. d. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct The average resting stroke volume of the heart is 70 mL and it beats ~72 times per minute. This would result in which cardiac output? Choose one answer. e. 5 L/minute Correct Which of the following hydrocarbons has a double bond in its carbon skeleton? Choose one answer. b. C2H4 Correct The average birth weight for human babies is about 3 kg. Which of the following terms best describes this? Choose one answer. a. stabilizing selection Correct Where and from what compound(s) is urea produced? Choose one answer. d. liver from NH3 and CO2 Correct Which of the following statements correctly defines a kilocalorie? Choose one answer. c. the amount of heat required to raise the temperature of 1 kg of water by 1°C Correct In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve? Choose one answer. d. It increases the surface for oxidative phosphoryation. Correct Which of these speed up heart rate? Choose one answer. a. epinephrine Correct Cyanide acts as a mitochondrial poison by blocking the final step in the electron transport chain. What will happen to human red blood cells if they are placed in an isotonic solution containing cyanide? Choose one answer. d. The cells will probably be unaffected. Correct The bonds that are broken when water vaporizes are Choose one answer. a. hydrogen bonds between water molecules. Correct Average blood pressure is lowest in which structure(s)? Choose one answer. d. venae cavae Correct Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. c. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. d. rabbits, horses, and herbivorous bears Correct Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. e. light is absorbed and funneled to reaction-center chlorophyll a. Correct Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? Choose one answer. e. The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. Correct Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. e. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct Which of the following statements is true of mammals? Choose one answer. d. The epiglottis prevents food from entering the trachea. Correct The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as Choose one answer. c. discovery science. Correct Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase? Choose one answer. d. It is an allosteric enzyme. Correct Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. Choose one answer. b. 2 ? 4 ? 1 ? 3 Correct Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend? Choose one answer. d. the ability of an enzyme to form a template for holding and joining molecules Correct Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct Photorespiration lowers the efficiency of photosynthesis by preventing the formation of Choose one answer. d. 3-phosphoglycerate molecules Correct Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. b. gain of water through food Correct Women with Turner syndrome have a genotype characterized as which of the following? Choose one answer. a. A karyotype of 45, X Correct Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. metaphase Correct A type of protein critical to all cells is organic catalysts called Choose one answer. d. enzymes. Correct Unlike an earthworm's metanephridia, a mammalian nephron Choose one answer. c. receives filtrate from blood instead of coelomic fluid. Correct Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply? Choose one answer. a. Photosystem I must be more ancestral. Correct Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. Answer: True False Incorrect Microbial symbionts are especially important for nutritional support in which of the following? Choose one answer b. herbivores and omnivores Correct Which of the following ionizes completely in solution and is considered to be a strong acid? Choose one answer. a. HCl Correct A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? Choose one answer. c. HT Correct Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. d. loop of Henle Correct When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of Choose one answer. b. negative feedback. Correct Grana, thylakoids, and stroma are all components found in Choose one answer. d. chloroplasts. Correct In negative pressure breathing, inhalation results from Choose one answer. e. contracting the diaphragm. Correct Which of the following are capable of converting light energy to chemical energy? Choose one answer. b. chloroplasts Correct A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? Choose one answer. c. Its gametes must have 23 chromosomes. Correct When muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by Choose one answer. b. increase in potassium ions. Correct Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. b. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that to keep the frogs in a smoke-filled environment for defined periods would result in lung cancer in the animals. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly) they knew that a more likely outcome would be which of the following? Choose one answer. c. skin cancer Correct A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. e. the activation energy barrier for this reaction cannot be surmounted. Correct During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from? Choose one answer. d. molecular oxygen (O2) Correct For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. a. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]? Choose one answer. b. seawater at pH 8 Correct Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not Choose one answer. b. perform controlled, precise reproduction. Correct Asexual reproduction results in identical offspring unless which of the following occurs? Choose one answer. c. Mutation Correct If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? Choose one answer. b. metaphase Correct If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? Choose one answer. e. n + 1; n + 1; n - 1; n - 1 Correct The human X and Y chromosomes Choose one answer. c. include genes that determine an individual's sex. Correct Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? Choose one answer. d. acetyl CoA Correct What is the primary function of the Calvin cycle? Choose one answer. d. synthesize simple sugars from carbon dioxide Correct Which describes the ABO blood group system? Choose one answer. b. Multiple alleles Correct How can one increase the rate of a chemical reaction? Choose one answer. e. Add a catalyst. Correct In which group of animals would you expect to find a relatively long cecum? Choose one answer. c. herbivores Correct In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald? Choose one answer. e. 75% Correct Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, whereas a different process that could have potentially contributed to the cluster's presence on more than one chromosome was __________. I. binary fission II. translation III. gene duplication IV. non-disjunction V. transcription Choose one answer. b. III, IV Correct When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes Choose one answer. d. oxidized. Correct The theory of evolution is most accurately described as Choose one answer. b. an overarching explanation, supported by much evidence, for how populations change over time. Correct Countercurrent exchange in the fish gill helps to maximize which of the following? Choose one answer. d. diffusion Correct A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. c. domain Eukarya, kingdom Fungi Correct Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? Choose one answer. c. gap junctions Correct Most CO2 from catabolism is released during Choose one answer. a. the citric acid cycle. Correct The body is capable of catabolizing many substances as sources of energy. Which of the followingwould be used as an energy source only after the depletion of other sources? Choose one answer. a. protein in muscle cells Correct Homologous chromosomes synapse and crossing over occurs. Choose one answer. d. The statement is true for meiosis I only. Correct Altering which of the following levels of structural organization could change the function of a protein? Choose one answer. a. all of the above Correct Familial hypercholesterolemia is characterized by which of the following? Choose one answer. c. defective LDL receptors on the cell membranes Correct Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore in which body systems would you expect most mitochondrial gene mutations to be exhibited? Choose one answer. d. Nervous and muscular systems Correct Approximately what percentage of the energy of glucose (C6H12O6) is transferred to storage in ATP as a result of the complete oxidation of glucose to CO2 and water in cellular respiration? Choose one answer. e. 40% Correct SRY is best described in which of the following ways? Choose one answer. b. A gene region present on the Y chromosome that triggers male development Correct Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes increase the rate of a reaction. Correct When does the synaptonemal complex disappear? Choose one answer. c. Late prophase of meiosis I Correct Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? Choose one answer. a. the synthesis of ATP Correct Which of the following nitrogenous wastes requires hardly any water for its excretion? Choose one answer. d. uric acid Correct Protists and bacteria are grouped into different domains because Choose one answer. e. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? Choose one answer d. 80 mm Hg Correct Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. c. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct The frequency of heterozygosity for the sickle cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? Choose one answer. d. Darwin's explanation of natural selection Correct Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. b. they cannot be manufactured by the organism. Correct Which of the following best describes enthalpy (H)? Choose one answer. c. the heat content of a chemical system Correct Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. d. nervous system, brain, nervous tissue, nerve cell Correct What is the substrate of salivary amylase? Choose one answer. c. starch Correct After ingestion, the first type of macromolecule to be worked on by enzymes in the human digestive system is Choose one answer. a. carbohydrate. Correct Organic chemistry is a science based on the study of Choose one answer. b. carbon compounds. Correct When you have a severe fever, what may be a grave consequence if this is not controlled? Choose one answer. e. change in the folding of enzymes Correct When a disease is said to have a multifactorial basis, it means that Choose one answer. c. both genetic and environmental factors contribute to the disease. Correct Cell membranes are asymmetrical. Which of the following is a most likely explanation? Choose one answer. e. Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. Correct Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? Choose one answer. b. ATP and NADPH Correct A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? Choose one answer. c. Archaea Correct Which of the following is not a normal response to increased blood osmolarity in humans? Choose one answer. a. production of more dilute urine Correct Which of the following is measured by an electrocardiogram? Choose one answer. a. the spread of impulses from the SA node Correct In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. b. harvest photons and transfer light energy to the reaction-center chlorophyll Correct Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. H2O ? NADPH ? Calvin cycle Correct Which of the following takes place as an ice cube cools a drink? Choose one answer. c. Kinetic energy in the drink decreases. Correct Which of the following enzymes works most effectively at a very low pH? Choose one answer. a. salivary amylase Incorrect b. trypsin Incorrect c. pancreatic lipase Incorrect d. pancreatic amylase Incorrect e. pepsin Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? Choose one answer. a. the high surface tension of water Incorrect b. the release of heat by the breaking of hydrogen bonds Incorrect c. reactions with other atmospheric compounds Incorrect d. the release of heat by the formation of hydrogen bonds Correct e. the change in density when it condenses to form a liquid or solid Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following is reflective of the phrase "the whole is greater than the sum of its parts"? Choose one answer. a. reductionism Incorrect b. feedback regulations Incorrect c. emergent properties Correct d. natural selection Incorrect e. high-throughput technology Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be Choose one answer. a. 56. Incorrect b. 16. Incorrect c. 12. Incorrect d. 14. Incorrect e. 28. Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is an example of polygenic inheritance? Choose one answer. a. Huntington's disease in humans Incorrect b. White and purple flower color in peas Incorrect c. Skin pigmentation in humans Correct d. Pink flowers in snapdragons Incorrect e. The ABO blood groups in humans Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The active site of an enzyme is the region that Choose one answer. a. binds the products of the catalytic reaction. Incorrect b. binds allosteric regulators of the enzyme. Incorrect c. is inhibited by the presence of a coenzyme or a cofactor. Incorrect d. is involved in the catalytic reaction of the enzyme. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction Choose one answer. a. loses electrons and gains energy. Incorrect b. neither gains nor loses electrons, but gains or loses energy. Incorrect c. loses electrons and loses energy. Correct d. gains electrons and loses energy. Incorrect e. gains electrons and gains energy. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Asexual reproduction and sexual reproduction differ in all but which of the following ways? Choose one answer. a. Individuals reproducing asexually transmit 100% of their genes to their progeny, whereas individuals reproducing sexually transmit only 50%. Incorrect b. Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized only by plants and animals. Correct c. Asexual reproduction involves a single parent, whereas sexual reproduction involves two. Incorrect d. Asexual reproduction requires only mitosis, whereas sexual reproduction always involves meiosis. Incorrect e. Asexual reproduction produces offspring that are genetically identical to the parents, whereas sexual reproduction gives rise to genetically distinct offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect b. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct c. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect d. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect e. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. vasa recta Correct b. proximal tubule Incorrect c. loop of Henle Incorrect d. Bowman's capsule Incorrect e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Why is it important to know what microscopy method was used to prepare the images you wish to study? Choose one answer. a. so that you can judge whether the images you are seeing are of cells or of organelles Incorrect b. so that you can interpret the correct biochemical process that is occurring Incorrect c. so that you can decide whether the image is actually of the size described Incorrect d. so that you can make a judgment about the likelihood of artifacts having been introduced in the preparation Correct e. so that you can know whether to view the image in color or not Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 The average resting stroke volume of the heart is 70 mL and it beats ~72 times per minute. This would result in which cardiac output? Choose one answer. a. 5 L/minute Correct b. 500 L/minute Incorrect c. 0.5 L/minute Incorrect d. 50 L/minute Incorrect e. 504 mL/minute Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called Choose one answer. a. ATPases. Incorrect b. proton pumps. Incorrect c. centrioles. Incorrect d. kinetochores. Incorrect e. cyclins. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Which of these is a statement that Darwin would have rejected? Choose one answer. a. Individuals can acquire new characteristics as they respond to new environments or situations. Incorrect b. Inherited variation in a population is a necessary precondition for natural selection to operate. Incorrect c. Natural populations tend to produce more offspring than the environment can support. Incorrect d. Environmental change plays a role in evolution. Incorrect e. The smallest entity that can evolve is an individual organism. Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following statements is representative of the second law of thermodynamics? Choose one answer. a. Cells require a constant input of energy to maintain their high level of organization. Correct b. Conversion of energy from one form to another is always accompanied by some gain of free energy. Incorrect c. Every energy transformation by a cell decreases the entropy of the universe. Incorrect d. Without an input of energy, organisms would tend toward decreasing entropy. Incorrect e. Heat represents a form of energy that can be used by most organisms to do work. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population's gene pool at a locus that had formerly been fixed? Choose one answer. a. Average number of loci Incorrect b. Nucleotide variability Incorrect c. Average heterozygosity Correct d. Geographic variability Incorrect Correct Marks for this submission: 1/1. Question 54 Marks: 1 The advantage of excreting wastes as urea rather than as ammonia is that Choose one answer. a. urea does not affect the osmolar gradient. Incorrect b. urea requires more water for excretion than ammonia. Incorrect c. less nitrogen is removed from the body. Incorrect d. urea can be exchanged for Na+. Incorrect e. urea is less toxic than ammonia. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? Choose one answer. a. The sizes of the structures in adult members of both species are similar in size. Incorrect b. The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. Correct c. Both species are well adapted to their particular environments. Incorrect d. Both species reproduce sexually. Incorrect e. The two species live at great distance from each other. Incorrect Correct Marks for this submission: 1/1. Question 56 Marks: 1 Where and from what compound(s) is urea produced? Choose one answer. a. kidneys from glucose Incorrect b. kidneys from glycerol and fatty acids Incorrect c. liver from glycogen Incorrect d. liver from NH3 and CO2 Correct e. bladder from uric acid and H2O Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. fermentation and chemiosmosis Incorrect b. glycolysis and fermentation Correct c. citric acid cycle Incorrect d. oxidative phosphorylation Incorrect e. oxidation of pyruvate to acetyl CoA Incorrect Correct Marks for this submission: 1/1. Question 58 Marks: 1 Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? Choose one answer. a. centrosome Correct b. chromatid Incorrect c. centromere Incorrect d. kinetochore Incorrect e. centriole Incorrect Correct Marks for this submission: 1/1. Question 59 Marks: 1 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? Choose one answer. a. a change in the shape of the nucleus Correct b. the inability of the cell to withstand enzymatic digestion Incorrect c. the loss of all nuclear function Incorrect d. failure of chromosomes to carry genetic information Incorrect e. inability of the nucleus to keep out destructive chemicals Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? Choose one answer. a. The two strands of the double helix would separate. Incorrect b. The purines would be separated from the deoxyribose sugars. Incorrect c. The phosphodiester linkages between deoxyribose sugars would be broken. Correct d. The pyrimidines would be separated from the deoxyribose sugars. Incorrect e. All bases would be separated from the deoxyribose sugars. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 4 Started on Saturday, January 17, 2009, 08:29 AM Completed on Saturday, January 17, 2009, 08:31 AM Time taken 1 min 52 secs Raw score 7/60 (12%) Grade out of a maximum of Question 1 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. birds. Incorrect b. desert tortoises. Incorrect c. kangaroo rats. Correct d. humans. Incorrect e. frogs. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Physical anthropologists locating the jaw bones of previously unknown vertebrate animal fossils are often able to assess the animal's diet especially because of clues from which of the following? Choose one answer. a. the prevalence of specific kinds of teeth Correct b. whether the mouth is the most anterior structure Incorrect c. the position of muscle attachment sites Incorrect d. the size of the mouth opening Incorrect e. the evidence of food molecules still present Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 The ATP made during fermentation is generated by which of the following? Choose one answer. a. oxidative phosphorylation Incorrect b. the electron transport chain Incorrect c. chemiosmosis Incorrect d. aerobic respiration Incorrect e. substrate-level phosphorylation Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 How can one increase the rate of a chemical reaction? Choose one answer. a. Increase the entropy of the reactants. Incorrect b. Add a catalyst. Correct c. Cool the reactants. Incorrect d. Decrease the concentration of the reactants. Incorrect e. Increase the activation energy needed. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following statements is a logical consequence of the second law of thermodynamics? Choose one answer. a. Every energy transfer requires activation energy from the environment. Incorrect b. If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. Incorrect c. Every chemical reaction must increase the total entropy of the universe. Correct d. If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. Incorrect e. Energy can be transferred or transformed, but it cannot be created or destroyed. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it Choose one answer. a. would function only as a base because of the amino group. Incorrect b. would function as neither an acid nor a base. Incorrect c. would function as both an acid and a base. Correct d. would function only as an acid because of the carboxyl group. Incorrect e. is impossible to determine how it would function. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 In what way were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth? Choose one answer. a. Only early Earth had an oxidizing atmosphere. Incorrect b. Less ultraviolet radiation penetrated Earth's early atmosphere. Incorrect c. Only early Earth had water vapor in its atmosphere. Incorrect d. Earth's early atmosphere had significant quantities of ozone. Incorrect e. Only early Earth was intensely bombarded by large space debris. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. can be made by the animal's body from other substances. Correct b. must be ingested in the diet. Incorrect c. is less important than an essential amino acid. Incorrect d. is not used by the animal in biosynthesis. Incorrect e. is not found in many proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The residual volume of the lungs decreases. Incorrect b. The epiglottis closes. Incorrect c. The rib cage expands. Incorrect d. The volume of the thoracic cavity decreases. Correct e. The diaphragm contracts. Incorrect Correct Marks for this submission: 1/1. Question 10 Marks: 1 Air rushes into the lungs of humans during inhalation because Choose one answer. a. pulmonary muscles contract and pull on the outer surface of the lungs. Incorrect b. pressure in the alveoli increases. Incorrect c. gas flows from a region of lower pressure to a region of higher pressure. Incorrect d. a positive respiratory pressure is created when the diaphragm relaxes. Incorrect e. the rib muscles and diaphragm contract, increasing the lung volume. Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Generation of proton gradients across membranes occurs during Choose one answer. a. photosynthesis. Incorrect b. respiration. Incorrect c. photorespiration. Incorrect d. neither photosynthesis nor respiration. Incorrect e. both photosynthesis and respiration. Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? Choose one answer. a. inability of chromosomes to meet at the metaphase plate Incorrect b. lack of appropriate cell death Correct c. metastasis Incorrect d. changes in the order of cell cycle stages Incorrect e. inability to form spindles Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is composed of chemical building blocks called nucleotides. Incorrect b. Genes are composed of deoxyribonucleic acid. Incorrect c. DNA is an enzyme that puts together amino acids to make a protein. Correct d. DNA is a code for the sequence of amino acids in a protein. Incorrect e. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The plant's height is 25 centimeters (cm). Incorrect b. The contents of the stomach are mixed every 20 seconds. Incorrect c. The six pairs of robins hatched an average of three chicks. Incorrect d. The temperature decreased from 20°C to 15°C. Incorrect e. The fish swam in a zig-zag motion. Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following describes peristalsis in the digestive system? Choose one answer. a. a common cause of loss of appetite, fatigue, and dehydration Incorrect b. smooth muscle contractions that move food through the alimentary canal Correct c. voluntary control of the rectal sphincters regulating defecation Incorrect d. the transport of nutrients to the liver through the hepatic portal vessel Incorrect e. a process of fat emulsification in the small intestine Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will Choose one answer. a. rapidly increase. Incorrect b. rapidly decline. Incorrect c. gradually increase. Incorrect d. remain unchanged. Incorrect e. gradually decline. Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 What is a chromatid? Choose one answer. a. another name for the chromosomes found in genetics Incorrect b. a special region that holds two centromeres together Incorrect c. a replicate chromosome Correct d. a chromosome in G1 of the cell cycle Incorrect e. a chromosome found outside the nucleus Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, whereas a different process that could have potentially contributed to the cluster's presence on more than one chromosome was __________. I. binary fission II. translation III. gene duplication IV. non-disjunction V. transcription Choose one answer. a. I, II Incorrect b. III, IV Correct c. III, V Incorrect d. II, III Incorrect e. II, V Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? Choose one answer. a. a cell's ability to distinguish one type of neighboring cell from another Correct b. maintaining the integrity of a fluid mosaic membrane Incorrect c. facilitated diffusion of molecules down their concentration gradients Incorrect d. maintaining membrane fluidity at low temperatures Incorrect e. active transport of molecules against their concentration gradients Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Most genes have many more than two alleles. However, which of the following is also true? Choose one answer. a. At least one allele for a gene always produces a dominant phenotype. Incorrect b. Most of the alleles will never be found in a live-born organism. Incorrect c. There may still be only two phenotypes for the trait. Correct d. All of the alleles but one will produce harmful effects if homozygous. Incorrect e. More than two alleles in a genotype is lethal. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. a. the starch solution has less free energy than the sugar solution. Incorrect b. starch cannot be hydrolyzed in the presence of so much water. Incorrect c. starch hydrolysis is nonspontaneous. Incorrect d. the activation energy barrier for this reaction cannot be surmounted. Correct e. the hydrolysis of starch to sugar is endergonic. Incorrect Correct Marks for this submission: 1/1. Question 22 Marks: 1 Which of these statements is false? Choose one answer. a. In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). Incorrect b. At sexual maturity, ovaries and testes produce diploid gametes by meiosis. Correct c. In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. Incorrect d. Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. Incorrect e. Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. interaction with the environment Incorrect b. evolution Incorrect c. reductionism Correct d. structure and function Incorrect e. emergent properties Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight when denied air. Curiously, the consumption of sugar increases as air is removed from the organism's environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the organism does fine. Which of the following best describes the organism? Choose one answer. a. It is an anaerobic organism. Incorrect b. It is a normal eukaryotic organism. Incorrect c. The organism obviously lacks the citric acid cycle and electron transport chain. Incorrect d. It must use a molecule other than oxygen to accept electrons from the electron transport chain. Incorrect e. It is a facultative anaerobe. Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 New combinations of linked genes are due to which of the following? Choose one answer. a. Crossing over Correct b. Nondisjunction Incorrect c. Mixing of sperm and egg Incorrect d. Deletions Incorrect e. Independent assortment Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? Choose one answer. a. ADP, Pi, and NADP+ Incorrect b. CO2 and glucose Incorrect c. electrons and H+ Incorrect d. ATP and NADPH Correct e. H2O and O2 Incorrect Correct Marks for this submission: 1/1. Question 27 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 12 Incorrect b. 2 Incorrect c. 1 Incorrect d. 38 Incorrect e. 6 Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. Bowman's capsule Incorrect b. glomerulus Incorrect c. loop of Henle Correct d. collecting duct Incorrect e. proximal convoluted tubule Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 What is the source of the extra chromosome 21 in an individual with Down syndrome? Choose one answer. a. Nondisjunction or translocation in either parent Correct b. Duplication of the chromosome Incorrect c. Nondisjunction in the father only Incorrect d. It is impossible to detect with current technology Incorrect e. Nondisjunction in the mother only Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, -S Correct b. +G, +H, +S Incorrect c. -G, +H, +S Incorrect d. +G, -H, -S Incorrect e. -G, -H, -S Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Where do the enzymatic reactions of the Calvin cycle take place? Choose one answer. a. thylakoid space Incorrect b. thylakoid membranes Incorrect c. outer membrane of the chloroplast Incorrect d. electron transport chain Incorrect e. stroma of the chloroplast Correct Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. a boy mowing grass Incorrect b. water rushing over Niagara Falls Incorrect c. an insect foraging for food Incorrect d. a firefly using light flashes to attract a mate Incorrect e. a food molecule made up of energy-rich macromolecules Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following steps has not yet been accomplished by scientists studying the origin of life? Choose one answer. a. abiotic synthesis of organic molecules Incorrect b. formation of protobionts that use DNA to direct the polymerization of amino acids Correct c. abiotic synthesis of polypeptides Incorrect d. formation of molecular aggregates with selectively permeable membranes Incorrect e. synthesis of small RNA polymers by ribozymes Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which life cycle stage is found in plants but not animals? Choose one answer. a. Gamete Incorrect b. Zygote Incorrect c. Multicellular haploid Correct d. Unicellular diploid Incorrect e. Multicellular diploid Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Fungi Correct c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Plantae Incorrect e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which of the following descriptions best fits the class of molecules known as nucleotides? Choose one answer. a. a pentose sugar and a purine or pyrimidine Incorrect b. a nitrogenous base, a phosphate group, and a pentose sugar Correct c. a phosphate group and an adenine or uracil Incorrect d. a nitrogenous base and a phosphate group Incorrect e. a nitrogenous base and a pentose sugar Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 ? HCO3- + H+ If the pH of the blood drops, one would expect Choose one answer. a. the concentration of bicarbonate ion (HCO3-) to increase. Incorrect b. the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3. Incorrect c. the concentration of hydroxide ion (OH-) to increase. Incorrect d. the HCO3- to act as a base and remove excess H+ with the formation of H2CO3. Correct e. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. Incorrect Correct Marks for this submission: 1/1. Question 38 Marks: 1 Familial hypercholesterolemia is characterized by which of the following? Choose one answer. a. poor attachment of the cholesterol to the extracellular matrix of cells Incorrect b. a general lack of glycolipids in the blood cell membranes Incorrect c. a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes Incorrect d. inhibition of the cholesterol active transport system in red blood cells Incorrect e. defective LDL receptors on the cell membranes Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. oxygen Incorrect b. NADH Correct c. pyruvate Incorrect d. lactate Incorrect e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 What is unique about transport epithelial cells in the ascending loop of Henle in humans? Choose one answer. a. They are the largest epithelial cells in the body. Incorrect b. They are not affected by high levels of nitrogenous wastes. Incorrect c. They are not in contact with interstitial fluid. Incorrect d. Their membranes are impermeable to water. Correct e. 50% of their cell mass is comprised of smooth endoplasmic reticulum. Incorrect Correct Marks for this submission: 1/1. Question 41 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. ureter Incorrect b. urethra Incorrect c. podocytes Incorrect d. juxtamedullary nephrons Correct e. Bowman's capsule Incorrect Correct Marks for this submission: 1/1. Question 42 Marks: 1 Cystic fibrosis (CF) is a Mendelian disorder in the human population that is inherited as a recessive. Two normal parents have two children with CF. The probability of their next child being normal for this characteristic is which of the following? Choose one answer. a. 0 Incorrect b. 1/2 Incorrect c. 1/4 Correct d. 1/8 Incorrect e. 3/4 Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. act as oxidizing agents Incorrect b. both oxidize and reduce during electron transport Correct c. donate electrons Incorrect d. transport protons within the mitochondria and chloroplasts Incorrect e. act as reducing agents Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which event is nearest in time to the end of the period known as snowball Earth? Choose one answer. a. evolution of true multicellularity Incorrect b. oxygenation of Earth's seas and atmosphere Incorrect c. Permian extinction Incorrect d. evolution of mitochondria Incorrect e. Cambrian explosion Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that to keep the frogs in a smoke-filled environment for defined periods would result in lung cancer in the animals. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly) they knew that a more likely outcome would be which of the following? Choose one answer. a. the amphibian equivalent of hypertension Incorrect b. diminished absorption of oxygen Incorrect c. tracheal tube abnormalities Incorrect d. gill abnormalities in the next generation of tadpoles Incorrect e. skin cancer Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following statements correctly describes geometric isomers? Choose one answer. a. They have variations in arrangement around a double bond. Correct b. They have the same chemical properties. Incorrect c. Their atoms and bonds are arranged in different sequences. Incorrect d. They have different molecular formulas. Incorrect e. They have an asymmetric carbon that makes them mirror images. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 A woman has six sons. The chance that her next child will be a daughter is Choose one answer. a. 0. Incorrect b. 5/6. Incorrect c. 1/6. Incorrect d. 1. Incorrect e. 1/2. Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct b. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect c. transfers large molecules as easily as small ones. Incorrect d. is very selective as to which subprotein sized molecules are transferred. Incorrect e. results from active transport. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Emphysema is a disease, frequently caused by smoking, that results in loss of the elastic elements of lung tissue. The effect will be more like which of the following? Choose one answer. a. an increase in airway resistance Correct b. pulmonary edema in which the alveoli amass fluid Incorrect c. a decrease in airway resistance Incorrect d. bronchiolar constriction as in asthma Incorrect e. cystic fibrosis in which mucus builds up in the lungs Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Thyroid hormone is increased. Incorrect b. Both insulin and glucagon decrease. Incorrect c. Both insulin and glucagon increase. Incorrect d. Blood glucagon increases. Correct e. Blood insulin increases. Incorrect Correct Marks for this submission: 1/1. Question 51 Marks: 1 Which of the following statements about genes is incorrect? Choose one answer. a. Genes correspond to segments of DNA. Incorrect b. Many genes contain the information needed for cells to synthesize enzymes and other proteins. Incorrect c. One gene only is used in a specific cell type. Correct d. During fertilization, both the sperm and the ovum contribute genes to the resulting fertilized egg. Incorrect e. Genetic differences can result from changes in the DNA called mutations. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped to make possible the evolution of the tetrapod limb. This type of change is illustrative of Choose one answer. a. paedomorphosis. Incorrect b. the influence of environment on development. Incorrect c. gene duplication. Incorrect d. heterochrony. Incorrect e. a change in a developmental gene or in its regulation that altered the spatial organization of body parts. Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following produces and modifies polysaccharides that will be secreted? Choose one answer. a. Golgi apparatus Correct b. vacuole Incorrect c. lysosome Incorrect d. mitochondrion Incorrect e. peroxisome Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular component ends up in the supernatant or the pellet is Choose one answer. a. the percentage of carbohydrates in the component. Incorrect b. the relative solubility of the component. Incorrect c. the size and weight of the component. Correct d. the number of enzymes in the fraction. Incorrect e. the presence or absence of lipids in the component. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 The ATP made during glycolysis is generated by Choose one answer. a. photophosphorylation. Incorrect b. electron transport. Incorrect c. substrate-level phosphorylation. Correct d. chemiosmosis. Incorrect e. oxidation of NADH to NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 How many grams of acetic acid (C2H4O2) would you use to make 10 L of a 0.1 M aqueous solution of acetic acid? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) Choose one answer. a. 6.0 g Incorrect b. 10.0 g Incorrect c. 0.1 g Incorrect d. 0.6 g Incorrect e. 60.0 g Correct Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 A patient has a blood pressure of 120/75, a pulse rate of 40 beats/min, a stroke volume of 70 mL/beat, and a respiratory rate of 25 breaths/min. This person's cardiac output per minute will be Choose one answer. a. 2,800 mL. Correct b. 500 mL. Incorrect c. 1,750 mL. Incorrect d. 4,800 mL. Incorrect e. 1,000 mL. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which structure is not part of the endomembrane system? Choose one answer. a. chloroplast Correct b. plasma membrane Incorrect c. Golgi apparatus Incorrect d. nuclear envelope Incorrect e. ER Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Where are the molecules of the electron transport chain found in plant cells? Choose one answer. a. inner membrane of mitochondria Incorrect b. cytoplasm Incorrect c. thylakoid membranes of chloroplasts Correct d. matrix of mitochondria Incorrect e. stroma of chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. a sufficient colony of H. pylori Incorrect b. high level of secretion from parietal cells Incorrect c. mucus secretion and active mitosis of epithelial cells Correct d. secretions entering the stomach from the pancreas Incorrect e. high level of secretion by chief cells Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 5 Started on Saturday, January 17, 2009, 08:32 AM Completed on Saturday, January 17, 2009, 08:33 AM Time taken 1 min 39 secs Raw score 14/60 (23%) Grade out of a maximum of Question 1 Marks: 1 Compared to the seawater around them, most marine invertebrates are Choose one answer. a. isoosmotic. Correct b. hyperosmotic. Incorrect c. hypoosmotic. Incorrect d. hyperosmotic and isoosmotic. Incorrect e. hypoosmotic and isoosmotic. Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 Evolution is biology's core theme that ties together all the other themes. This is because evolution explains Choose one answer. a. why distantly related organisms sometimes resemble each other. Incorrect b. how organisms become adapted to their environment through the differential reproductive success of varying individuals. Incorrect c. the unity and diversity of life. Incorrect d. explains why some organisms have traits in common. Incorrect e. all of the above Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. can be made by the animal's body from other substances. Correct b. is not used by the animal in biosynthesis. Incorrect c. is less important than an essential amino acid. Incorrect d. must be ingested in the diet. Incorrect e. is not found in many proteins. Incorrect Correct Marks for this submission: 1/1. Question 4 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) is greater than item (B). Incorrect b. Item (A) may stand in more than one of the above relations to item (B). Incorrect c. Item (A) is less than item (B). Incorrect d. Item (A) is exactly or very approximately equal to item (B). Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 The blood level of which gas is most important in controlling human respiration rate? Choose one answer. a. carbon dioxide Correct b. nitric acid Incorrect c. carbon monoxide Incorrect d. oxygen Incorrect e. nitrogen Incorrect Correct Marks for this submission: 1/1. Question 6 Marks: 1 Which statement about natural selection is most correct? Choose one answer. a. Adaptations beneficial at one time should generally be beneficial during all other times as well. Incorrect b. Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well. Incorrect c. Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes. Incorrect d. Natural selection is the sole means by which populations can evolve. Incorrect e. Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals. Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following normally occurs whether or not oxygen (O2) is present? Choose one answer. a. citric acid cycle Incorrect b. oxidative phosphorylation (chemiosmosis) Incorrect c. fermentation Incorrect d. oxidation of pyruvate to acetyl CoA Incorrect e. glycolysis Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The existence of the phenomenon of exaptation is most closely associated with which of the following reasons that natural selection cannot fashion perfect organisms? Choose one answer. a. Natural selection and sexual selection can work at cross-purposes to each other. Incorrect b. Adaptations are often compromises. Incorrect c. Chance events affect the evolutionary history of populations in environments that can change unpredictably. Incorrect d. Evolution is limited by historical constraints. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? Choose one answer. a. 104M Incorrect b. 4% Incorrect c. 10-10M Incorrect d. 4.0 M Incorrect e. 10-4M Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a Choose one answer. a. lower osmotic pressure. Incorrect b. higher PO2. Correct c. higher PCO2. Incorrect d. lower pH. Incorrect e. greater bicarbonate concentration. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. kidneys of vertebrates Correct b. metanephridia of earthworms Incorrect c. Malpighian tubules of insects Incorrect d. protonephridia of rotifers Incorrect e. flame-bulb system of flatworms Incorrect Correct Marks for this submission: 1/1. Question 12 Marks: 1 Among known plant species, which of these have been the two most commonly occurring phenomena leading to the origin of new species? 1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy Choose one answer. a. 2 and 4 Correct b. 1 and 3 Incorrect c. 2 and 3 Incorrect d. 1 and 4 Incorrect Correct Marks for this submission: 1/1. Question 13 Marks: 1 What is the hydroxide ion concentration of the lake described in question 7? Choose one answer. a. 10 M Incorrect b. 10-4M Incorrect c. 10-14 M Incorrect d. 10-10M Correct e. 10-7M Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect b. DNA is composed of chemical building blocks called nucleotides. Incorrect c. DNA is an enzyme that puts together amino acids to make a protein. Correct d. Genes are composed of deoxyribonucleic acid. Incorrect e. DNA is a code for the sequence of amino acids in a protein. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila in which of these ways? Choose one answer. a. The entire Drosophila genome has approximately 400 map units. Incorrect b. There are four major functional classes of genes in Drosophila. Incorrect c. Drosophila genes cluster into four distinct groups of linked genes. Correct d. The overall number of genes in Drosophila is a multiple of four. Incorrect e. Drosophila genes have, on average, four different alleles. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur? Choose one answer. a. Cells would carry on the Calvin cycle at a much slower rate. Incorrect b. More sugars would be produced. Incorrect c. There would be more light-induced damage to the cells. Incorrect d. Cells would carry on more photosynthesis. Incorrect e. Less ATP would be generated. Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a[[no]] Choose one answer. a. noncompetitive inhibitor of the enzyme. Incorrect b. competitive inhibitor of the enzyme. Incorrect c. allosteric activator of the enzyme. Incorrect d. cofactor necessary for enzyme activity. Correct e. coenzyme derived from a vitamin. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following metabolic processes can occur without a net influx of energy from some other process? Choose one answer. a. C6H12O6 + 6 O2 ? 6 CO2 + 6H2O Correct b. glucose + fructose ? sucrose Incorrect c. amino acids ? protein Incorrect d. 6 CO2 + 6 H2O ? C6H12O6 + 6 O2 Incorrect e. ADP + Pi ? ATP + H2O Incorrect Correct Marks for this submission: 1/1. Question 19 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A greater-than-normal volume of isoosmotic urine would be produced. Correct b. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect c. A less-than-normal volume of isoosmotic urine would be produced. Incorrect d. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect e. No urine would be produced. Incorrect Correct Marks for this submission: 1/1. Question 20 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. active transport Incorrect b. selective reabsorption Correct c. filtration Incorrect d. secretion Incorrect e. ultrafiltration Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that Choose one answer. a. the nuclear envelope is physically continuous with the endoplasmic reticulum. Incorrect b. small vesicles from the Golgi fuse with the nuclear envelope. Incorrect c. nuclear pore complexes contain proteins. Incorrect d. at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. Correct e. the nuclear envelope is not part of the endomembrane system. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is Choose one answer. a. PGAL. Incorrect b. RuBP. Incorrect c. glucose. Incorrect d. PGA. Incorrect e. O2. Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They can have very long carbon skeletons. Incorrect b. They are easily reduced. Incorrect c. They have no nitrogen in their makeup. Incorrect d. They have a lot of electrons associated with hydrogen. Correct e. They have a lot of oxygen atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. NADPH ? electron transport chain ? O2 Incorrect b. H2O ? NADPH ? Calvin cycle Correct c. NADPH ? chlorophyll ? Calvin cycle Incorrect d. NADPH ? O2 ? CO2 Incorrect e. H2O ? photosystem I ? photosystem II Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? Choose one answer. a. The number of phosphates is three instead of two. Incorrect b. The nitrogen-containing base is different. Incorrect c. The number of phosphates is three instead of one. Incorrect d. The sugar molecule is different. Incorrect e. There is no difference. Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon increase. Incorrect b. Both insulin and glucagon decrease. Incorrect c. Thyroid hormone is increased. Incorrect d. Blood glucagon increases. Correct e. Blood insulin increases. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 The cyclin component of MPF is destroyed toward the end of this phase: Choose one answer. a. G0 Incorrect b. G1 Incorrect c. S Incorrect d. G2 Incorrect e. M Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. blood proteins Incorrect b. fat stored in the liver Incorrect c. muscle proteins Incorrect d. fat stored in adipose tissue Incorrect e. muscle and liver glycogen Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Eukarya, kingdom Fungi Correct b. domain Bacteria, kingdom Prokaryota Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Archaea, kingdom Bacteria Incorrect e. domain Eukarya, kingdom Plantae Incorrect Correct Marks for this submission: 1/1. Question 30 Marks: 1 When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype? Choose one answer. a. 50% Correct b. 100% Incorrect c. 75% Incorrect d. 0% Incorrect e. 25% Incorrect Correct Marks for this submission: 1/1. Question 31 Marks: 1 Genomic imprinting is generally due to the addition of methyl (-CH3) groups to C nucleotides in order to silence a given gene. If this depends on the sex of the parent who transmits the gene, which of the following must be true? Choose one answer. a. The imprints are transmitted only to gamete-producing cells. Incorrect b. Genes required for early development stages must not be imprinted. Incorrect c. Methylation must be reversible in ovarian and testicular cells. Correct d. Methylation of this kind must occur more in males than in females. Incorrect e. Methylation of C is permanent in a gene. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes? Choose one answer. a. a cell that is digesting food particles Incorrect b. a cell that is enlarging its vacuole Incorrect c. a cell that is producing cytoplasmic enzymes Correct d. a cell that is constructing its cell wall or extracellular matrix Incorrect e. a cell that is secreting proteins Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. a. proteins and nucleic acids. Correct b. starch and cellulose. Incorrect c. fatty acids and glycerol. Incorrect d. triglycerides and steroids. Incorrect e. phospholipids and glycolipids. Incorrect Correct Marks for this submission: 1/1. Question 34 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. heat and fluorescence Incorrect b. ADP and NADP Incorrect c. ATP and P700 Incorrect d. P700 and P680 Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Why is it important that an experiment include a control group? Choose one answer. a. Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor. Correct b. The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results. Incorrect c. A control group assures that an experiment will be repeatable. Incorrect d. The control group provides a reserve of experimental subjects. Incorrect e. A control group is required for the development of an "if, then" statement. Incorrect Correct Marks for this submission: 1/1. Question 36 Marks: 1 What is the mechanism for the production of genetic recombinants? Choose one answer. a. Methylation of cytosine Incorrect b. Deletions and duplications during meiosis Incorrect c. Crossing over and independent assortment Correct d. X inactivation Incorrect e. Nondisjunction Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. NAD+. Incorrect b. pyruvate. Incorrect c. water. Incorrect d. oxygen. Correct e. ADP. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Why isn't the mitochondrion classified as part of the endomembrane system? Choose one answer. a. It is not attached to the outer nuclear envelope. Incorrect b. It only has two membrane layers. Incorrect c. Its structure is not derived from the ER. Correct d. It has too many vesicles. Incorrect e. It is not involved in protein synthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 What is the reason that linked genes are inherited together? Choose one answer. a. Alleles are paired together during meiosis. Incorrect b. They are located close together on the same chromosome. Correct c. Chromosomes are unbreakable. Incorrect d. The number of genes in a cell is greater than the number of chromosomes. Incorrect e. Genes align that way during metaphase I of meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. a. rabbits, horses, and herbivorous bears Correct b. tapeworms and other intestinal parasites Incorrect c. humans and other primates Incorrect d. carnivorous animals Incorrect e. tubeworms that digest via symbionts Incorrect Correct Marks for this submission: 1/1. Question 41 Marks: 1 The mathematical expression for the change in free energy of a system is G =H-TS. Which of the following is (are) correct? Choose one answer. a. H is the change in entropy, the energy available to do work. Incorrect b. G is the change in free energy. Correct c. S is the change in enthalpy, a measure of randomness. Incorrect d. T is the temperature in degrees Celsius. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants Choose one answer. a. the spindles contain microfibrils in addition to microtubules, whereas animal spindles do not contain microfibrils. Incorrect b. sister chromatids are identical, but they differ from one another in animals. Incorrect c. chromosomes become attached to the spindle at prophase, whereas in animals chromosomes do not become attached until anaphase. Incorrect d. a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. Correct e. spindle poles contain centrioles, whereas spindle poles in animals do not. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 2 Incorrect b. 12 Incorrect c. 6 Correct d. 1 Incorrect e. 38 Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect b. a system to circulate gases, nutrients, and wastes to and from cells Correct c. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect d. a system of individualized exchange tubules for each cell group Incorrect e. direct exchange of nutrients with the surrounding medium Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect b. protein function at one site affected by binding at another of its active sites Incorrect c. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect d. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect e. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. hemoglobin. Correct b. plasma proteins. Incorrect c. plasma buffers. Incorrect d. carbonic acid. Incorrect e. carbon dioxide. Incorrect Correct Marks for this submission: 1/1. Question 47 Marks: 1 The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? Choose one answer. a. spindle attachment to kinetochores Incorrect b. spindle formation Incorrect c. cleavage furrow formation Correct d. DNA synthesis Incorrect e. cell elongation during anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Tidal volume in respiration is analogous to what measurement in cardiac physiology? Choose one answer. a. diastolic pressure Incorrect b. heart rate Incorrect c. stroke volume Correct d. systolic pressure Incorrect e. cardiac output Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 You have in your possession a microscope slide with meiotic cells on it and a light microscope. What would you look for if you wanted to identify metaphase I cells on the slide? Choose one answer. a. A visible nuclear envelope Incorrect b. Tetrads lined up at the center of the cell Correct c. A cleavage furrow Incorrect d. Separated sister chromatids at each pole of the cell Incorrect e. A synaptonemal complex Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that Choose one answer. a. humans and chimpanzees share a relatively recent common ancestor. Correct b. humans evolved from chimpanzees. Incorrect c. chimpanzees evolved from humans. Incorrect d. convergent evolution led to the DNA similarities. Incorrect e. humans and chimpanzees are not closely related. Incorrect Correct Marks for this submission: 1/1. Question 51 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. oxygen and carbon dioxide Incorrect b. electrons and photons Incorrect c. ATP and NADPH Correct d. water and carbon Incorrect e. carbon dioxide and RuBP Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not Choose one answer. a. possess a selectively permeable membrane boundary. Incorrect b. perform osmosis. Incorrect c. grow in size. Incorrect d. absorb compounds from the external environment. Incorrect e. perform controlled, precise reproduction. Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? Choose one answer. a. The cytochromes phosphorylate ADP to form ATP. Incorrect b. ATP synthase pumps protons by active transport. Incorrect c. NAD+ is oxidized. Incorrect d. The pH of the matrix increases. Correct e. The electrons gain free energy. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 If the pH of a solution is increased from pH 5 to pH 7, it means that the Choose one answer. a. concentration of OH- is one-hundredth (0.01X) what it was at pH 5. Incorrect b. concentration of H+ is 100 times greater and the concentration of OH- is one-hundredth what they were at pH 5. Incorrect c. concentration of H+ is twice (2X) what it was at pH 5. Incorrect d. concentration of H+ is half (1/2) what it was at pH 5. Incorrect e. concentration of OH- is 100 times greater than what it was at pH 5. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following would probably contribute to constipation? A substance that Choose one answer. a. contains plenty of fiber. Incorrect b. stimulates peristalsis. Incorrect c. decreases water reabsorption in the large intestine. Incorrect d. speeds up movement of material in the large intestine. Incorrect e. promotes water reabsorption in the large intestine. Correct Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? Choose one answer. a. by increasing the percentage of cholesterol molecules in the membrane Incorrect b. by increasing the percentage of unsaturated phospholipids in the membrane Correct c. by co-transport of glucose and hydrogen Incorrect d. by using active transport Incorrect e. by decreasing the number of hydrophobic proteins in the membrane Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? Choose one answer. a. the high surface tension of water Incorrect b. the release of heat by the breaking of hydrogen bonds Incorrect c. the release of heat by the formation of hydrogen bonds Correct d. reactions with other atmospheric compounds Incorrect e. the change in density when it condenses to form a liquid or solid Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in Choose one answer. a. G2. Incorrect b. prophase. Incorrect c. metaphase. Incorrect d. G1 Correct e. anaphase. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? Choose one answer. a. non-polarity of the drug molecule Incorrect b. blood or tissue type of the patient Incorrect c. lack of charge on the drug molecule Incorrect d. lipid composition of the target cells' plasma membrane Incorrect e. similarity of the drug molecule to other molecules transported by the target cells Correct Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. a. organ system, tissue, molecule, cell Incorrect b. organ system, nervous tissue, brain Incorrect c. brain, organ system, nerve cell, nervous tissue Incorrect d. organism, organ system, tissue, cell, organ Incorrect e. nervous system, brain, nervous tissue, nerve cell Correct Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 6 Started on Saturday, January 17, 2009, 08:34 AM Completed on Saturday, January 17, 2009, 08:35 AM Time taken 1 min 34 secs Raw score 14/60 (23%) Grade out of a maximum of Question 1 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. none of the above Incorrect b. reduce FAD+ to FADH2. Incorrect c. reduce NAD+ to NADH. Incorrect d. oxidize NADH to NAD+. Correct e. reduce FADH2 to FAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of Choose one answer. a. ATP, pyruvate, and oxygen. Incorrect b. ATP, CO2, and lactate. Incorrect c. ATP, pyruvate, and acetyl CoA. Incorrect d. ATP, NADH, and pyruvate. Incorrect e. ATP, CO2, and ethanol (ethyl alcohol). Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Recent evidence points to the conclusion that the ancestral finches of the Galapagos originated in the islands of the Caribbean. Answer: True Correct False Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Most cells cannot harness heat to perform work because Choose one answer. a. heat is not a form of energy. Incorrect b. cells do not have much heat; they are relatively cool. Incorrect c. heat can never be used to do work. Incorrect d. heat denatures enzymes. Incorrect e. temperature is usually uniform throughout a cell. Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 At what temperature is water at its densest? Choose one answer. a. 100°C Incorrect b. 0°C Incorrect c. 4°C Correct d. 32°C Incorrect e. 212°C Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? Choose one answer. a. prophase Incorrect b. anaphase Incorrect c. metaphase Correct d. telophase Incorrect e. interphase Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 A defining characteristic of allopatric speciation is Choose one answer. a. artificial selection. Incorrect b. large populations. Incorrect c. the appearance of new species in the midst of old ones. Incorrect d. geographic isolation. Correct e. asexually reproducing populations. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. photosynthesis. Incorrect b. neither photosynthesis nor respiration. Correct c. both photosynthesis and respiration. Incorrect d. photorespiration. Incorrect e. respiration. Incorrect Correct Marks for this submission: 1/1. Question 9 Marks: 1 Of the following, which cell structure would most likely be visible with a light microscope that has been manufactured to the maximum resolving power possible? Choose one answer. a. largest microfilament Incorrect b. nuclear pore Incorrect c. microtubule Incorrect d. ribosome Incorrect e. mitochondrion Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Where does glycolysis takes place? Choose one answer. a. mitochondrial matrix Incorrect b. cytosol Correct c. mitochondrial outer membrane Incorrect d. mitochondrial intermembrane space Incorrect e. mitochondrial inner membrane Incorrect Correct Marks for this submission: 1/1. Question 11 Marks: 1 Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's Choose one answer. a. endothermic level. Incorrect b. free-energy content. Incorrect c. activation energy. Correct d. heat content. Incorrect e. entropy. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. water and carbon Incorrect b. electrons and photons Incorrect c. carbon dioxide and RuBP Incorrect d. oxygen and carbon dioxide Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. secretion Incorrect b. filtration Incorrect c. ultrafiltration Incorrect d. selective reabsorption Correct e. active transport Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Natural selection and recombination due to crossing over during meiosis I are related in which of the following ways? Choose one answer. a. Recombination does not affect natural selection. Incorrect b. Recombinants may have combinations of traits that are favored by natural selection. Correct c. Most recombinants reproduce less frequently than do non-recombinants. Incorrect d. Non-recombinant organisms are usually favored by natural selection if there is environmental change. Incorrect e. Recombinants are usually selected against. Incorrect Correct Marks for this submission: 1/1. Question 15 Marks: 1 Which of the following organs is incorrectly paired with its function? Choose one answer. a. small intestinenutrient absorption Incorrect b. large intestinebile production Correct c. oral cavitystarch digestion Incorrect d. pancreasenzyme production Incorrect e. stomachprotein digestion Incorrect Correct Marks for this submission: 1/1. Question 16 Marks: 1 Which is one of the main energy transformers of cells? Choose one answer. a. vacuole Incorrect b. mitochondrion Correct c. lysosome Incorrect d. peroxisome Incorrect e. Golgi apparatus Incorrect Correct Marks for this submission: 1/1. Question 17 Marks: 1 Which of the following factors would tend to increase membrane fluidity? Choose one answer. a. a relatively high protein content in the membrane Incorrect b. a greater proportion of saturated phospholipids Incorrect c. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses Incorrect d. a greater proportion of unsaturated phospholipids Correct e. a lower temperature Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? Choose one answer. a. The two strands of the double helix would separate. Incorrect b. The purines would be separated from the deoxyribose sugars. Incorrect c. The phosphodiester linkages between deoxyribose sugars would be broken. Correct d. The pyrimidines would be separated from the deoxyribose sugars. Incorrect e. All bases would be separated from the deoxyribose sugars. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of these conditions should completely prevent the occurrence of natural selection in a population over time? Choose one answer. a. The population lives in a habitat where there are no competing species present. Incorrect b. The environment is changing at a relatively slow rate. Incorrect c. All variation between individuals is due only to environmental factors. Correct d. The population size is large. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Extracellular compartmentalization of digestive processes is an evolutionary adaptation in many animal phyla. Which of the following phyla is correctly paired with the compartment that first evolved in that phylum? Choose one answer. a. Cnidariagastrovascular cavity Incorrect b. Arthropodastomach Incorrect c. Molluscalarge intestine Incorrect d. Annelidacomplete alimentary canal Correct e. Chordataliver Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which of the following is not a normal response to increased blood osmolarity in humans? Choose one answer. a. reduced urine production Incorrect b. increased thirst Incorrect c. production of more dilute urine Correct d. increased permeability of the collecting duct to water Incorrect e. release of ADH by the pituitary gland Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. The reaction would change from endergonic to exergonic. Incorrect b. Nothing; the reaction would stay at equilibrium. Correct c. Additional product would be formed. Incorrect d. The free energy of the system would change. Incorrect e. Additional substrate would be formed. Incorrect Correct Marks for this submission: 1/1. Question 23 Marks: 1 Which of the following features do all gas exchange systems have in common? Choose one answer. a. They are found only in animals. Incorrect b. They are enclosed within ribs. Incorrect c. The exchange surfaces are moist. Correct d. They are maintained at a constant temperature. Incorrect e. They are exposed to air. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? Choose one answer. a. It must be a primate. Incorrect b. It must be human. Incorrect c. Its gametes must have 23 chromosomes. Correct d. It must be an animal. Incorrect e. It must be sexually reproducing. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Males are more often affected by sex-linked traits than females because Choose one answer. a. males are hemizygous for the X chromosome. Correct b. male hormones such as testosterone often alter the effects of mutations on the X chromosome. Incorrect c. female hormones such as estrogen often compensate for the effects of mutations on the X. Incorrect d. X chromosomes in males generally have more mutations than X chromosomes in females. Incorrect e. mutations on the Y chromosome often worsen the effects of X-linked mutations. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following processes of osmoregulation by the kidney is the least selective? Choose one answer. a. H+ pumping to control pH Incorrect b. filtration Correct c. salt pumping to control osmolarity Incorrect d. secretion Incorrect e. reabsorption Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. positive feedback. Correct b. feedback inhibition. Incorrect c. a bioinformatic system. Incorrect d. enzymatic catalysis. Incorrect e. negative feedback. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which type of bond must be broken for water to vaporize? Choose one answer. a. ionic bonds Incorrect b. hydrogen bonds Correct c. nonpolar covalent bonds Incorrect d. polar covalent bonds Incorrect e. covalent bonds Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? Choose one answer. a. Living organisms do not follow the laws of thermodynamics. Incorrect b. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. Incorrect c. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth. Correct d. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe. Incorrect e. Living organisms are able to transform energy into entropy. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Calico cats are female because Choose one answer. a. multiple crossovers on the Y chromosome prevent orange pigment production. Incorrect b. a male inherits only one of the two X-linked genes controlling hair color. Correct c. the males die during embryonic development. Incorrect d. the Y chromosome has a gene blocking orange coloration. Incorrect e. only females can have Barr bodies. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following is true of urea? It is Choose one answer. a. insoluble in water. Incorrect b. more toxic to human cells than ammonia. Incorrect c. the primary nitrogenous waste product of most birds. Incorrect d. the primary nitrogenous waste product of humans. Correct e. the primary nitrogenous waste product of most aquatic invertebrates. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following factors would not contribute to allopatric speciation? Choose one answer. a. The separated population is small, and genetic drift occurs. Incorrect b. Different mutations begin to distinguish the gene pools of the separated populations. Incorrect c. A population becomes geographically isolated from the parent population. Incorrect d. Gene flow between the two populations is extensive. Correct e. The isolated population is exposed to different selection pressures than the ancestral population. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which statement describes the functioning of photosystem II? Choose one answer. a. The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit. Incorrect b. The electron vacancies in P680 are filled by electrons derived from water. Correct c. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. Incorrect d. Light energy excites electrons in the electron transport chain in a photosynthetic unit. Incorrect e. The splitting of water yields molecular carbon dioxide as a by-product. Incorrect Correct Marks for this submission: 1/1. Question 34 Marks: 1 Natural selection is most nearly the same as Choose one answer. a. differential reproductive success. Correct b. non-random mating. Incorrect c. genetic drift. Incorrect d. gene flow. Incorrect e. diploidy. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. nitrite Incorrect b. ammonia Incorrect c. nitrate Incorrect d. urea Incorrect e. uric acid Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which of the following statements is correct about diffusion? Choose one answer. a. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration. Correct b. It requires an expenditure of energy by the cell. Incorrect c. It is very rapid over long distances. Incorrect d. It requires integral proteins in the cell membrane. Incorrect e. It is an active process in which molecules move from a region of lower concentration to one of higher concentration. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of these makes determining the evolutionary relatedness of different species based on the amino acid sequence of homologous proteins generally less accurate than determinations of relatedness based on the nucleotide sequences of homologous genes? Choose one answer. a. Independent assortment Incorrect b. Silent mutations Correct c. Gene duplications Incorrect d. Crossing-over Incorrect e. Translocation events that change gene sequences Incorrect Correct Marks for this submission: 1/1. Question 38 Marks: 1 Which of the following relationships between cell structures and their respective functions is correct? Choose one answer. a. lysosomes: formation of ATP Incorrect b. cell wall: support, protection Incorrect c. ribosomes: secretion Incorrect d. chromosomes: cytoskeleton of the nucleus Incorrect e. chloroplasts: chief sites of cellular respiration Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 What is the term for metabolic pathways that release stored energy by breaking down complex molecules? Choose one answer. a. thermodynamic pathways Incorrect b. fermentation pathways Incorrect c. catabolic pathways Correct d. anabolic pathways Incorrect e. bioenergetic pathways Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which term describes two centrosomes arranged at opposite poles of the cell? Choose one answer. a. prometaphase Correct b. anaphase Incorrect c. prophase Incorrect d. metaphase Incorrect e. telophase Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. blue, green, and red Incorrect b. blue and violet Correct c. green and yellow Incorrect d. green, blue, and yellow Incorrect e. red and yellow Incorrect Correct Marks for this submission: 1/1. Question 42 Marks: 1 In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle? Choose one answer. a. regeneration of ATP from ADP Incorrect b. regeneration of rubisco Correct c. inactivation of RuBP carboxylase enzyme Incorrect d. addition of a pair of electrons from NADPH Incorrect e. a gain of NADPH Incorrect Correct Marks for this submission: 1/1. Question 43 Marks: 1 What is a genome? Choose one answer. a. A specialized polymer of four different kinds of monomers Incorrect b. A specific segment of DNA that is found within a prokaryotic chromosome Incorrect c. An ordered display of chromosomes arranged from largest to smallest Incorrect d. A specific set of polypeptides within each cell Incorrect e. The complete complement of an organism's genes Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 In which blood vessel is glucose concentration likely to vary the most? Choose one answer. a. coronary arteries Incorrect b. hepatic vein, which drains the liver Incorrect c. pulmonary veins Incorrect d. abdominal artery Incorrect e. hepatic portal vessel Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, +S Incorrect b. -G, -H, -S Incorrect c. +G, -H, -S Incorrect d. -G, +H, +S Incorrect e. +G, +H, -S Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. a. Every organism has the potential to produce more offspring than the local environment can support. Incorrect b. Slight inheritable variations within a population may make an individual significantly more or less likely to survive in its environment, and thus to reproduce. Incorrect c. Most individuals in a species do not survive to reproduce. Incorrect d. Characteristics of organisms are inherited as genes on chromosomes. Correct e. Better adapted members of a species will survive and reproduce more successfully. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Obesity in humans is most likely to contribute to which of the following? Choose one answer. a. type I diabetes and prostate cancer Incorrect b. type II diabetes and muscle atrophy Incorrect c. type I diabetes and breast cancer Incorrect d. type II diabetes and cardiovascular disease Correct e. type II diabetes and decreased insulin production Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A woman has six sons. The chance that her next child will be a daughter is Choose one answer. a. 5/6. Incorrect b. 1/6. Incorrect c. 0. Incorrect d. 1/2. Correct e. 1. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 The blood level of which gas is most important in controlling human respiration rate? Choose one answer. a. nitric acid Incorrect b. carbon dioxide Correct c. oxygen Incorrect d. carbon monoxide Incorrect e. nitrogen Incorrect Correct Marks for this submission: 1/1. Question 50 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect b. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect c. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect d. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct e. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A common form of regulation in which accumulation of an end product of a process slows that process is called positive feedback. Answer: True Incorrect False Correct Correct Marks for this submission: 1/1. Question 52 Marks: 1 At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype? Choose one answer. a. Early prophase Incorrect b. Late telophase Incorrect c. Late anaphase or early telophase Incorrect d. Anaphase Incorrect e. Late prophase or metaphase Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following lung volumes would be different in a person at rest compared with when the person exercises? Choose one answer. a. total lung capacity Incorrect b. residual volume Incorrect c. All of the above would be different. Incorrect d. tidal volume Correct e. vital capacity Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Foods eaten by animals are most often composed largely of macromolecules. This requires the animals to have methods for which of the following? Choose one answer. a. enzymatic hydrolysis Correct b. elimination Incorrect c. dehydration synthesis Incorrect d. demineralization Incorrect e. regurgitation Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of these speed up heart rate? Choose one answer. a. low-density lipoproteins Incorrect b. immunoglobulins Incorrect c. platelets Incorrect d. epinephrine Correct e. erythropoietin Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of these is a correct representation of the hierarchy of biological organization from least to most complex? Choose one answer. a. organelle of a stomach cell, digestive system, large intestine, small intestine, intestinal tissue, organism Incorrect b. molecule, small intestine, large intestine, intestinal tissue, digestive system, organism Incorrect c. molecule, digestive system, digestive cell organelle, small intestine, large intestine, intestinal cell, organism Incorrect d. molecule, intestinal cell organelle, intestinal cell, intestinal tissue, digestive system, organism Correct e. organelle of an intestinal cell, digestive system, small intestine, large intestine, intestinal tissue, organism Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following couples chemiosmosis to energy storage? Choose one answer. a. ATP synthase Correct b. NADH Incorrect c. FADH2 Incorrect d. electron transport Incorrect e. cytochromes Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 What is the structural feature that allows DNA to replicate? Choose one answer. a. sugar-phosphate backbone Incorrect b. complementary pairing of the nitrogenous bases Correct c. twisting of the molecule to form an a helix Incorrect d. three-component structure of the nucleotides Incorrect e. disulfide bonding (bridging) of the two helixes Incorrect Correct Marks for this submission: 1/1. Question 59 Marks: 1 A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause? Choose one answer. a. The woman inherited this tendency from her parents. Incorrect b. One member of the couple underwent nondisjunction in gamete production. Correct c. One member of the couple underwent nondisjunction in somatic cell production. Incorrect d. One member of the couple carried a translocation. Incorrect Correct Marks for this submission: 1/1. Question 60 Marks: 1 Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen? Choose one answer. a. a steroid such as testosterone Incorrect b. a hydrocarbon such as benzene Incorrect c. a monosaccharide such as glucose Incorrect d. an alcohol such as ethanol Incorrect e. an amino acid such as glycine Correct Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 7 Started on Saturday, January 17, 2009, 08:35 AM Completed on Saturday, January 17, 2009, 08:37 AM Time taken 1 min 42 secs Raw score 10/60 (17%) Grade out of a maximum of Question 1 Marks: 1 How many electron pairs does carbon share in order to complete its valence shell? Choose one answer. a. 3 Incorrect b. 1 Incorrect c. 4 Correct d. 8 Incorrect e. 2 Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 PKU (phenylketonuria) is a hereditary condition in which infants and young children cannot ingest any more than tiny amounts of the amino acid phenylalanine without serious neurological results. This damage can be prevented by a severe restriction of phenylalanine in the diet. Which of the following is the nutritional concept that forms the basis for this preventive treatment? Choose one answer. a. essential nutrients Correct b. enzymatic hydrolysis Incorrect c. structural anatomy of the brain Incorrect d. dehydration synthesis Incorrect e. symbiosis Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Reduction of oxygen which forms water occurs during Choose one answer. a. photosynthesis. Incorrect b. both photosynthesis and respiration. Incorrect c. photorespiration. Incorrect d. respiration. Correct e. neither photosynthesis nor respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? Choose one answer. a. 1:1 male to female Incorrect b. 3:1 male to female Incorrect c. 1:2 male to female Incorrect d. 2:1 male to female Correct e. 4:3 male to female Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Why did the improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics? Choose one answer. a. It led to the discovery of mitochondria. Incorrect b. It allowed the study of meiosis and mitosis, revealing parallels between behaviors of genes and chromosomes. Correct c. It allowed scientists to see the DNA present within chromosomes. Incorrect d. It showed genes functioning to direct the formation of enzymes. Incorrect e. It revealed new and unanticipated features of Mendel's pea plant varieties. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which cell would be best for studying lysosomes? Choose one answer. a. muscle cell Incorrect b. bacterial cell Incorrect c. phagocytic white blood cell Correct d. leaf cell of a plant Incorrect e. nerve cell Incorrect Correct Marks for this submission: 1/1. Question 7 Marks: 1 The application of scientific knowledge for some specific purpose is known as Choose one answer. a. technology. Correct b. pure science. Incorrect c. inductive science. Incorrect d. anthropologic science. Incorrect e. deductive science. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which statement describes the functioning of photosystem II? Choose one answer. a. The splitting of water yields molecular carbon dioxide as a by-product. Incorrect b. The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit. Incorrect c. Light energy excites electrons in the electron transport chain in a photosynthetic unit. Incorrect d. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. Incorrect e. The electron vacancies in P680 are filled by electrons derived from water. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it Choose one answer. a. would function as neither an acid nor a base. Incorrect b. would function as both an acid and a base. Correct c. would function only as a base because of the amino group. Incorrect d. is impossible to determine how it would function. Incorrect e. would function only as an acid because of the carboxyl group. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? Choose one answer. a. The pH of the matrix increases. Correct b. The cytochromes phosphorylate ADP to form ATP. Incorrect c. NAD+ is oxidized. Incorrect d. The electrons gain free energy. Incorrect e. ATP synthase pumps protons by active transport. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 When does the synaptonemal complex disappear? Choose one answer. a. Late metaphase of meiosis II Incorrect b. Late prophase of meiosis I Correct c. Early anaphase of meiosis I Incorrect d. During fertilization or fusion of gametes Incorrect e. Mid-prophase of meiosis II Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 A 100 mL beaker contains 10 mL of NaOH solution at pH = 13. A technician carefully pours into the beaker, 10 mL of HCl at pH = 1. Which of the following statements correctly describes the results of this mixing? Choose one answer. a. The pH of the beaker's contents falls. Correct b. The concentration of Na+ ion rises. Incorrect c. The pH of the beaker's contents rises. Incorrect d. The concentration of Cl- ion falls. Incorrect e. The concentration of undissociated H2O molecules remains unchanged. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Nerve and muscle cells are in this phase: Choose one answer. a. M Incorrect b. G1 Incorrect c. S Incorrect d. G0 Correct e. G2 Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of these are not embedded in the lipid bilayer at all? Choose one answer. a. peripheral proteins Correct b. transmembrane proteins Incorrect c. integral proteins Incorrect d. glycoproteins Incorrect e. integrins Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following nitrogenous wastes requires hardly any water for its excretion? Choose one answer. a. amino acid Incorrect b. urea Incorrect c. ammonia Incorrect d. nitrogen gas Incorrect e. uric acid Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The peroxisome gets its name from its interaction with hydrogen peroxide. If a liver cell is detoxifying alcohol and some other poisons, it does so by removal of hydrogen from the molecules. What, then, do the enzymes of the peroxisome do? Choose one answer. a. transfer the harmful substances to the mitochondria Incorrect b. transfer the hydrogens to oxygen molecules Correct c. combine the hydrogen with ATP Incorrect d. use the hydrogen to break down hydrogen peroxide Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is composed of chemical building blocks called nucleotides. Incorrect b. Genes are composed of deoxyribonucleic acid. Incorrect c. DNA is an enzyme that puts together amino acids to make a protein. Correct d. DNA is a code for the sequence of amino acids in a protein. Incorrect e. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. reductionism Correct b. emergent properties Incorrect c. structure and function Incorrect d. interaction with the environment Incorrect e. evolution Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following is not a normal response to increased blood osmolarity in humans? Choose one answer. a. increased permeability of the collecting duct to water Incorrect b. release of ADH by the pituitary gland Incorrect c. reduced urine production Incorrect d. increased thirst Incorrect e. production of more dilute urine Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Unlike an earthworm's metanephridia, a mammalian nephron Choose one answer. a. has a transport epithelium. Incorrect b. forms urine by changing fluid composition inside a tubule. Incorrect c. functions in both osmoregulation and excretion. Incorrect d. receives filtrate from blood instead of coelomic fluid. Correct e. is intimately associated with a capillary network. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which group possess excretory organs known as Malpighian tubules? Choose one answer. a. flatworms Incorrect b. earthworms Incorrect c. jellyfish Incorrect d. insects Correct e. sea stars Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Where do air-breathing insects carry out gas exchange? Choose one answer. a. in specialized internal gills Incorrect b. across the thin cuticular exoskeleton Incorrect c. in the alveoli of their lungs Incorrect d. in specialized external gills Incorrect e. across the membranes of cells Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following about the law of segregation is false? Choose one answer. a. It can account for the 3:1 ratio seen in the F2 generation of Mendel's crosses. Incorrect b. It is a method that can be used to determine the number of chromosomes in a plant. Correct c. It states that each of two alleles for a given trait segregate into different gametes. Incorrect d. It can be explained by the segregation of homologous chromosomes during meiosis. Incorrect e. It can be used to predict the likelihood of transmission of certain genetic diseases within families. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would be the effect? Choose one answer. a. The heart rate would be decreased. Incorrect b. Atria and ventricles would contract at about the same time. Correct c. No apparent effect on heart activity would be observed. Incorrect d. Only the ventricles would contract. Incorrect e. Only the atria would contract. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? Choose one answer. a. There is no consistent relationship. Incorrect b. The pH of the thylakoid space is higher than that anywhere else in the cell. Incorrect c. The pH within the thylakoid is less than that of the stroma. Correct d. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. Incorrect e. The pH of the stroma is higher than that of the other two measurements. Incorrect Correct Marks for this submission: 1/1. Question 26 Marks: 1 Protists and bacteria are grouped into different domains because Choose one answer. a. bacteria decompose protists. Incorrect b. bacteria are not made of cells. Incorrect c. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct d. protists are photosynthetic. Incorrect e. protists eat bacteria. Incorrect Correct Marks for this submission: 1/1. Question 27 Marks: 1 Which of the following is a fat-soluble vitamin? Choose one answer. a. calcium Incorrect b. vitamin C Incorrect c. vitamin B12 Incorrect d. vitamin A Correct e. iodine Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 A chemical reaction that has a positive G is correctly described as Choose one answer. a. endothermic. Incorrect b. enthalpic. Incorrect c. exothermic. Incorrect d. spontaneous. Incorrect e. endergonic. Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2? 6 CO2 + 6 H2O + Energy Choose one answer. a. C6H12O6 is oxidized and O2 is reduced. Correct b. CO2 is reduced and O2 is oxidized. Incorrect c. O2 is reduced and CO2 is oxidized. Incorrect d. O2 is oxidized and H2O is reduced. Incorrect e. C6H12O6 is reduced and CO2 is oxidized. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. a sufficient colony of H. pylori Incorrect b. high level of secretion by chief cells Incorrect c. mucus secretion and active mitosis of epithelial cells Correct d. secretions entering the stomach from the pancreas Incorrect e. high level of secretion from parietal cells Incorrect Correct Marks for this submission: 1/1. Question 31 Marks: 1 Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this? Choose one answer. a. Incomplete dominance Incorrect b. Pleiotropy Correct c. Multiple alleles Incorrect d. Epistasis Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that Choose one answer. a. an unseen guiding force is at work. Incorrect b. evolution always tends toward increased complexity or increased size. Incorrect c. in particular environments, similar adaptations can be beneficial in more than one species. Correct d. a larger volume-to-surface area ratio is beneficial to all mammals. Incorrect e. evolution generally progresses toward some predetermined goal. Incorrect Correct Marks for this submission: 1/1. Question 33 Marks: 1 The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? Choose one answer. a. It will be on the cytoplasmic side of the ER. Correct b. It will be on the side facing the interior of the ER. Incorrect c. It could be facing in either direction because the orientation of proteins is scrambled in the Golgi apparatus. Incorrect d. It doesn't matter, because the pump is not active in the ER. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Homologous chromosomes move toward opposite poles of a dividing cell during Choose one answer. a. mitosis. Incorrect b. binary fission. Incorrect c. meiosis II. Incorrect d. fertilization. Incorrect e. meiosis I. Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 According to the induced fit hypothesis of enzyme catalysis, which of the following is correct? Choose one answer. a. A competitive inhibitor can outcompete the substrate for the active site. Incorrect b. The binding of the substrate depends on the shape of the active site. Incorrect c. The binding of the substrate changes the shape of the enzyme's active site. Correct d. Some enzymes change their structure when activators bind to the enzyme. Incorrect e. The active site creates a microenvironment ideal for the reaction. Incorrect Correct Marks for this submission: 1/1. Question 36 Marks: 1 An important group of peripheral membrane proteins are enzymes, such as the phospholipases that attack the head groups of phospholipids leading to the degradation of damaged membranes. What properties must these enzymes exhibit? Choose one answer. a. lipid solubility Incorrect b. independence from cofactor interaction Incorrect c. resistance to degradation Incorrect d. membrane spanning domains Incorrect e. water solubility Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. a. Slight inheritable variations within a population may make an individual significantly more or less likely to survive in its environment, and thus to reproduce. Incorrect b. Every organism has the potential to produce more offspring than the local environment can support. Incorrect c. Characteristics of organisms are inherited as genes on chromosomes. Correct d. Most individuals in a species do not survive to reproduce. Incorrect e. Better adapted members of a species will survive and reproduce more successfully. Incorrect Correct Marks for this submission: 1/1. Question 38 Marks: 1 How many molecules of glycerol (C3H8O3) would be present in 1 L of a 1 M glycerol solution? Choose one answer. a. 1 Incorrect b. 92 Incorrect c. 6.02 × 1023 Correct d. 1 × 107 Incorrect e. 14 Incorrect Correct Marks for this submission: 1/1. Question 39 Marks: 1 Among enzymes, kinases catalyze phosphorylation, while phosphatases catalyze removal of phosphate(s). A cell's use of these enzymes can therefore function as an on-off switch for various processes. Which of the following is probably involved? Choose one answer. a. the change in a protein's charge leading to a conformational change Correct b. the excision of one or more peptides Incorrect c. the change in a protein's charge leading to cleavage Incorrect d. a change in the optimal temperature at which a reaction will occur Incorrect e. a change in the optimal pH at which a reaction will occur Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis? Choose one answer. a. nuclear membranes Incorrect b. chloroplast membranes Incorrect c. along the outer edge of the nucleoid Incorrect d. free in the cytosol Incorrect e. along the inner surface of the plasma membrane Correct Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 In mechanism, photophosphorylation is most similar to Choose one answer. a. the Calvin cycle. Incorrect b. substrate-level phosphorylation in glycolysis. Incorrect c. oxidative phosphorylation in cellular respiration. Correct d. reduction of NADP+. Incorrect e. carbon fixation. Incorrect Correct Marks for this submission: 1/1. Question 42 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon decrease. Incorrect b. Blood glucagon increases. Correct c. Blood insulin increases. Incorrect d. Both insulin and glucagon increase. Incorrect e. Thyroid hormone is increased. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following is (are) true for anabolic pathways? Choose one answer. a. They consume energy to build up polymers from monomers. Correct b. They are usually highly spontaneous chemical reactions. Incorrect c. They do not depend on enzymes. Incorrect d. They release energy as they degrade polymers to monomers. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of these stimulate the production of red blood cells? Choose one answer. a. epinephrine Incorrect b. erythropoietin Correct c. low-density lipoproteins Incorrect d. immunoglobulins Incorrect e. platelets Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 If we continued to follow the cell lineage from question 5, then the DNA content of a single cell at metaphase of meiosis II would be Choose one answer. a. 0.5x. Incorrect b. x. Correct c. 0.25x. Incorrect d. 4x. Incorrect e. 2x. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight when denied air. Curiously, the consumption of sugar increases as air is removed from the organism's environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the organism does fine. Which of the following best describes the organism? Choose one answer. a. It is a facultative anaerobe. Correct b. The organism obviously lacks the citric acid cycle and electron transport chain. Incorrect c. It is an anaerobic organism. Incorrect d. It is a normal eukaryotic organism. Incorrect e. It must use a molecule other than oxygen to accept electrons from the electron transport chain. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of these are involved in the early stages of blood clotting? Choose one answer. a. low-density lipoproteins Incorrect b. platelets Correct c. epinephrine Incorrect d. erythropoietin Incorrect e. immunoglobulins Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. a. starch and cellulose. Incorrect b. triglycerides and steroids. Incorrect c. phospholipids and glycolipids. Incorrect d. proteins and nucleic acids. Correct e. fatty acids and glycerol. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring? 1. immigration or emigration 2. directional selection 3. adaptation 4. genetic drift 5. disruptive selection Choose one answer. a. 4 and 5 Incorrect b. 1, 2, and 3 Incorrect c. 4 only Incorrect d. 2 and 3 Correct e. 1 only Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following is not an observation or inference on which natural selection is based? Choose one answer. a. Poorly adapted individuals never produce offspring. Correct b. Species produce more offspring than the environment can support. Incorrect c. Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less suited. Incorrect d. Only a fraction of the offspring produced by an individual may survive. Incorrect e. There is heritable variation among individuals. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct b. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect c. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect d. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect e. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following? Choose one answer. a. The allele for blue hydrangea being completely dominant Incorrect b. Environmental factors such as soil pH Correct c. The alleles being codominant Incorrect d. Acknowledging that multiple alleles are involved Incorrect e. The fact that a mutation has occurred Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not Choose one answer. a. perform controlled, precise reproduction. Correct b. grow in size. Incorrect c. possess a selectively permeable membrane boundary. Incorrect d. perform osmosis. Incorrect e. absorb compounds from the external environment. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In order for a protein to be an integral membrane protein it would have to be which of the following? Choose one answer. a. amphipathic Correct b. hydrophilic Incorrect c. hydrophobic Incorrect d. completely covered with phospholipids Incorrect e. exposed on only one surface of the membrane Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve? Choose one answer. a. It increases the surface for substrate-level phosphorylation. Incorrect b. It increases the surface for oxidative phosphoryation. Correct c. It allows for increased rate of glycolysis. Incorrect d. It allows the liver cell to have fewer mitochondria. Incorrect e. It allows for increased rate of the citric acid cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. enzymes Incorrect b. disaccharides Incorrect c. peptides Incorrect d. polymers Incorrect e. monomers Correct Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 What is the term for metabolic pathways that release stored energy by breaking down complex molecules? Choose one answer. a. bioenergetic pathways Incorrect b. thermodynamic pathways Incorrect c. fermentation pathways Incorrect d. anabolic pathways Incorrect e. catabolic pathways Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes? Choose one answer. a. 23 Incorrect b. About 8 million Correct c. 920 Incorrect d. 460 Incorrect e. 46 Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following are nitrogenous bases of the pyrimidine type? Choose one answer. a. guanine and adenine Incorrect b. thymine and guanine Incorrect c. adenine and thymine Incorrect d. cytosine and uracil Correct e. ribose and deoxyribose Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Gene flow is a concept best used to describe an exchange between Choose one answer. a. populations. Correct b. species. Incorrect c. males and females. Incorrect d. individuals. Incorrect e. chromosomes. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 8 Started on Saturday, January 17, 2009, 08:38 AM Completed on Saturday, January 17, 2009, 08:39 AM Time taken 1 min 39 secs Raw score 12/60 (20%) Grade out of a maximum of Question 1 Marks: 1 In the cells of some organisms, mitosis occurs without cytokinesis. This will result in Choose one answer. a. destruction of chromosomes. Incorrect b. cells that are unusually small. Incorrect c. cells with more than one nucleus. Correct d. cells lacking nuclei. Incorrect e. cell cycles lacking an S phase. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. reduce NAD+ to NADH. Incorrect b. reduce FADH2 to FAD+. Incorrect c. oxidize NADH to NAD+. Correct d. reduce FAD+ to FADH2. Incorrect e. none of the above Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level? Choose one answer. a. molecule, cell, organ system, population, ecosystem, biosphere Correct b. organism, community, biosphere, molecule, tissue, organ Incorrect c. organelle, tissue, biosphere, ecosystem, population, organism Incorrect d. ecosystem, cell, population, tissue, organism, organ system Incorrect e. cell, community, population, organ system, molecule, organelle Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following is (are) true for anabolic pathways? Choose one answer. a. They consume energy to build up polymers from monomers. Correct b. They do not depend on enzymes. Incorrect c. They are usually highly spontaneous chemical reactions. Incorrect d. They release energy as they degrade polymers to monomers. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 How does pyruvate enter the mitochondrion? Choose one answer. a. through a pore Incorrect b. through a channel Incorrect c. diffusion Incorrect d. active transport Correct e. facilitated diffusion Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Obesity in humans is most likely to contribute to which of the following? Choose one answer. a. type II diabetes and muscle atrophy Incorrect b. type I diabetes and breast cancer Incorrect c. type II diabetes and decreased insulin production Incorrect d. type II diabetes and cardiovascular disease Correct e. type I diabetes and prostate cancer Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 All the organisms on your campus make up Choose one answer. a. a community. Correct b. a population. Incorrect c. an ecosystem. Incorrect d. a taxonomic domain. Incorrect e. an experimental group. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of the following statements concerning prokaryotic and eukaryotic cells is not correct? Choose one answer. a. Eukaryotic cells contain a membrane-bound nucleus. Incorrect b. DNA, or deoxyribonucleic acid, is present in both prokaryotic cells and eukaryotic cells. Incorrect c. Prokaryotic cells lack a membrane-bound nucleus. Incorrect d. DNA or deoxyribonucleic acid is present in the nucleus of eukaryotic cells. Incorrect e. Prokaryotic cells contain small membrane-enclosed organelles. Correct Correct Marks for this submission: 1/1. Question 9 Marks: 1 When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the Choose one answer. a. reduction of NAD+. Incorrect b. creation of a proton gradient. Correct c. lowering of pH in the mitochondrial matrix. Incorrect d. formation of ATP. Incorrect e. restoration of the Na+/K+ balance across the membrane. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. gain of water through food Correct b. no drinking of water Incorrect c. loss of water through the gills Incorrect d. gain of salt through the gills Incorrect e. loss of water in the urine Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. Bowman's capsule Incorrect b. loop of Henle Incorrect c. collecting duct Incorrect d. proximal tubule Incorrect e. vasa recta Correct Correct Marks for this submission: 1/1. Question 12 Marks: 1 One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called? Choose one answer. a. Inversion Incorrect b. Disjunction Incorrect c. Translocation Correct d. Deletion Incorrect e. Duplication Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 An example of a hydrogen bond is the bond between Choose one answer. a. Mg+and Cl- in MgCl2. Incorrect b. C and H in methane (CH4). Incorrect c. Na+and Cl- in salt. Incorrect d. the two hydrogen atoms in a molecule of hydrogen gas (H2). Incorrect e. the H of one water molecule and the O of another water molecule. Correct Correct Marks for this submission: 1/1. Question 14 Marks: 1 We can be sure that a mole of table sugar and a mole of vitamin C are equal in their Choose one answer. a. volume. Incorrect b. number of atoms. Incorrect c. mass in daltons. Incorrect d. number of molecules. Correct e. mass in grams. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. tonoplast ? primary cell wall ? plasma membrane ? cytoplasm Incorrect b. plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect c. primary cell wall ? plasma membrane ? cytoplasm ? tonoplast Correct d. primary cell wall ? plasma membrane ? tonoplast ? cytoplasm ? vacuole Incorrect e. secondary cell wall ? plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet? Choose one answer. a. They interbreed in the region of overlap, but produce sterile offspring. Incorrect b. They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations. Correct c. They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap. Incorrect d. They no longer attempt to interbreed. Incorrect e. They interbreed freely and produce fertile hybrid offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then Choose one answer. a. plasma proteins will escape through the endothelium of the capillaries. Incorrect b. the pH of the interstitial fluids will increase. Incorrect c. most carbon dioxide will be bound to hemoglobin and carried away from tissues. Incorrect d. fluids will tend to accumulate in tissues. Correct e. hemoglobin will not release oxygen. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 In vertebrate animals, brown fat tissue's color is due to abundant mitochondria. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few mitochondria. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue? Choose one answer. a. to increase the production of ATP synthase Incorrect b. to allow the animals to regulate their metabolic rate when it is especially hot Incorrect c. to allow other membranes of the cell to perform mitochondrial function Incorrect d. to increase the rate of oxidative phosphorylation from its few mitochondria Incorrect e. to regulate temperature by converting energy from NADH oxidation to heat Correct Correct Marks for this submission: 1/1. Question 19 Marks: 1 Asexual reproduction and sexual reproduction differ in all but which of the following ways? Choose one answer. a. Individuals reproducing asexually transmit 100% of their genes to their progeny, whereas individuals reproducing sexually transmit only 50%. Incorrect b. Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized only by plants and animals. Correct c. Asexual reproduction involves a single parent, whereas sexual reproduction involves two. Incorrect d. Asexual reproduction produces offspring that are genetically identical to the parents, whereas sexual reproduction gives rise to genetically distinct offspring. Incorrect e. Asexual reproduction requires only mitosis, whereas sexual reproduction always involves meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? Choose one answer. a. salt Incorrect b. ammonia Correct c. NaOH Incorrect d. bicarbonate Incorrect e. glucose Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 On food packages, to what does the term "insoluble fiber" refer? Choose one answer. a. cellulose Correct b. polypeptides Incorrect c. chitin Incorrect d. starch Incorrect e. amylopectin Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. an insect foraging for food Incorrect b. a boy mowing grass Incorrect c. water rushing over Niagara Falls Incorrect d. a firefly using light flashes to attract a mate Incorrect e. a food molecule made up of energy-rich macromolecules Correct Correct Marks for this submission: 1/1. Question 23 Marks: 1 Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt × BBtt will have black fur and long tails? Choose one answer. a. 3/8 Incorrect b. 1/2 Correct c. 3/16 Incorrect d. 9/16 Incorrect e. 1/16 Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 During which phases of mitosis are chromosomes composed of two chromatids? Choose one answer. a. from metaphase through telophase Incorrect b. from G1 of interphase through metaphase Incorrect c. from anaphase through telophase Incorrect d. from G2 of interphase through metaphase Correct e. from interphase through anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? Choose one answer. a. All of these pairs are correct. Incorrect b. 5'-A-T-G-C-3' with 5'-G-C-A-T-3' Correct c. 5'-A-G-C-T-3' with 5'-T-C-G-A-3' Incorrect d. 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' Incorrect e. 5'-G-C-G-C-3' with 5'-T-A-T-A-3' Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Organic chemistry is currently defined as Choose one answer. a. the study of compounds made only by living cells. Incorrect b. the study of vital forces. Incorrect c. the study of hydrocarbons. Incorrect d. the study of natural (as opposed to synthetic) compounds. Incorrect e. the study of carbon compounds. Correct Correct Marks for this submission: 1/1. Question 27 Marks: 1 A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of Choose one answer. a. 4,000 mL. Incorrect b. 5,450 mL. Incorrect c. 4,450 mL. Incorrect d. 1,450 mL. Incorrect e. 5,000 mL. Correct Correct Marks for this submission: 1/1. Question 28 Marks: 1 Which of the following features do all gas exchange systems have in common? Choose one answer. a. They are enclosed within ribs. Incorrect b. They are exposed to air. Incorrect c. They are found only in animals. Incorrect d. The exchange surfaces are moist. Correct e. They are maintained at a constant temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 The conversion of fibrinogen to fibrin Choose one answer. a. is likely to occur too often in an individual with hemophilia. Incorrect b. occurs when fibrinogen is released from broken platelets. Incorrect c. is the final step of a clotting process that involves multiple clotting factors. Correct d. is linked to hypertension and may damage artery walls. Incorrect e. occurs within red blood cells. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 In terms of the hierarchical organization of life, a bacterium is at the __________ level of organization, whereas a human is at the __________ level of organization. Choose one answer. a. single tissue; multicellular organism Incorrect b. organelle; organ system Incorrect c. tissue; organism Incorrect d. single-celled organism; multicellular organism Correct e. single organelle; organism Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following is true of metabolism in its entirety? Choose one answer. a. Metabolism depends on a constant supply of energy from food Incorrect b. Metabolism is a property of organismal life Correct c. Metabolism manages the increase of entropy in an organism Incorrect d. Metabolism depends on an organism's adequate hydration Incorrect e. Metabolism utilizes all of an organism's resources Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? Choose one answer. a. spending several hours mowing the lawn on a hot day Correct b. drinking several glasses of water Incorrect c. sleeping Incorrect d. eating a pizza with olives and pepperoni Incorrect e. eating a bag of potato chips Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 The lowest level of biological organization that can perform all the activities required for life is the Choose one answer. a. cell–for example, a skin cell. Correct b. tissue–for example, nervous tissue. Incorrect c. organism–for example, an amoeba, dog, human, or maple tree. Incorrect d. organelle–for example, a chloroplast. Incorrect e. organ system–for example, the reproductive system. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 How does ADH function at the cellular level? Choose one answer. a. ADH stimulates the reabsorption of glucose through channel proteins. Incorrect b. It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water. Incorrect c. It causes membranes to include more phospholipids that have unsaturated fatty acids. Incorrect d. It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. Incorrect e. It causes an increase in the number of aquaporin molecules of collecting duct cells. Correct Correct Marks for this submission: 1/1. Question 35 Marks: 1 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? Choose one answer. a. failure of chromosomes to carry genetic information Incorrect b. the loss of all nuclear function Incorrect c. a change in the shape of the nucleus Correct d. inability of the nucleus to keep out destructive chemicals Incorrect e. the inability of the cell to withstand enzymatic digestion Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 In order for anaphase to begin, which of the following must occur? Choose one answer. a. Spindle microtubules must begin to depolymerize. Incorrect b. Chromatids must lose their kinetochores. Incorrect c. Cohesin must be cleaved enzymatically. Correct d. Kinetochores must attach to the metaphase plate. Incorrect e. Cohesin must attach the sister chromatids to each other. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following statements is representative of the second law of thermodynamics? Choose one answer. a. Heat represents a form of energy that can be used by most organisms to do work. Incorrect b. Conversion of energy from one form to another is always accompanied by some gain of free energy. Incorrect c. Cells require a constant input of energy to maintain their high level of organization. Correct d. Every energy transformation by a cell decreases the entropy of the universe. Incorrect e. Without an input of energy, organisms would tend toward decreasing entropy. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as Choose one answer. a. reversible inhibition. Incorrect b. allosteric inhibition. Incorrect c. noncooperative inhibition. Incorrect d. metabolic inhibition. Incorrect e. feedback inhibition. Correct Correct Marks for this submission: 1/1. Question 39 Marks: 1 During the process of digestion, fats are broken down when fatty acids are detached from glycerol. In addition, proteins are digested to yield amino acids. What do these two processes have in common? Choose one answer. a. They are catalyzed by the same enzyme. Incorrect b. They involve the addition of a water molecule to break bonds (hydrolysis). Correct c. Both occur intracellularly in most organisms. Incorrect d. Both require the presence of hydrochloric acid to lower the pH. Incorrect e. Each requires ATP as an energy source. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Where does the Calvin cycle take place? Choose one answer. a. stroma of the chloroplast Correct b. outer membrane of the chloroplast Incorrect c. chlorophyll molecule Incorrect d. thylakoid membrane Incorrect e. cytoplasm surrounding the chloroplast Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Large proteins such as albumin remain in capillaries rather than diffusing out. Which of the following does this cause? Choose one answer. a. increased diffusion of Hb Incorrect b. loss of fluid from capillaries Incorrect c. increased diffusion of CO2 Incorrect d. creation of an osmotic pressure difference across capillary walls Correct e. loss of osmotic pressure in the capillaries Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following statements correctly describes some aspect of protein disposal from prokaryotic cells? Choose one answer. a. Proteins that are excreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. Correct b. The mechanism of protein excretion in prokaryotes is probably the same as that in eukaryotes. Incorrect c. Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell. Incorrect d. In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell. Incorrect e. Prokaryotes are unlikely to be able to excrete proteins because they lack an endomembrane system. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 A certain kind of snail can have a right-handed direction of shell coiling (D) or left handed coiling (d). If direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a Dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)? Choose one answer. a. All Dd; half right and half left coiling Incorrect b. 1/2 Dd : 1/2 dd; all right coiling Correct c. All Dd; all left coiling Incorrect d. 1/2 Dd : 1/2 dd; half right and half left coiling Incorrect e. All Dd; all right coiling Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following does not occur during the Calvin cycle? Choose one answer. a. release of oxygen Correct b. consumption of ATP Incorrect c. oxidation of NADPH Incorrect d. carbon fixation Incorrect e. regeneration of the CO2 acceptor Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Where do the enzymatic reactions of the Calvin cycle take place? Choose one answer. a. stroma of the chloroplast Correct b. outer membrane of the chloroplast Incorrect c. electron transport chain Incorrect d. thylakoid space Incorrect e. thylakoid membranes Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Monkeys of South and Central America have prehensile tails, meaning that their tails can be used to grasp objects. The tails of African and Asian monkeys are not prehensile. Which discipline is most likely to provide an evolutionary explanation for how this difference in tails came about? Choose one answer. a. Aerodynamics Incorrect b. Biochemistry Incorrect c. Physiology Incorrect d. Biogeography Correct e. Botany Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Morgan and his colleagues worked out a set of symbols to represent fly genotypes. Which of the following are representative? Choose one answer. a. vg+vgse+se × vgvgsese Correct b. AaBb × AaBb Incorrect c. 46, XY or 46, XX Incorrect d. +2 × +3 Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which of the following statements is true? Choose one answer. a. The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%. Incorrect b. The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. Correct c. Crossing over occurs during prophase II of meiosis. Incorrect d. All of the traits that Mendel studiedseed color, pod shape, flower color, and othersare due to genes linked on the same chromosome. Incorrect e. Linked genes are found on different chromosomes. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon decrease. Incorrect b. Blood glucagon increases. Correct c. Both insulin and glucagon increase. Incorrect d. Blood insulin increases. Incorrect e. Thyroid hormone is increased. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 The sodium-potassium pump is called an electrogenic pump because it Choose one answer. a. pumps equal quantities of Na+ and K+ across the membrane. Incorrect b. is used to drive the transport of other molecules against a concentration gradient. Incorrect c. contributes to the membrane potential. Correct d. ionizes sodium and potassium atoms. Incorrect e. pumps hydrogen ions out of the cell. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 If two continental land masses converge and are united, then the collision should cause Choose one answer. a. a decrease in climatic extremes in the interior of the new super-continent. Incorrect b. the extinction of any species adapted to intertidal and coastal habitats. Incorrect c. an overall decrease in the surface area located in the continental interior. Incorrect d. the maintenance of the previously existing ocean currents and wind patterns. Incorrect e. a net loss of intertidal zone and coastal habitat. Correct Correct Marks for this submission: 1/1. Question 52 Marks: 1 Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? Choose one answer. a. oxidative phosphorylation Incorrect b. chemiosmosis Incorrect c. electron transport Incorrect d. glycolysis Correct e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 A rapid method of speciation that has been important in the history of flowering plants is Choose one answer. a. genetic drift. Incorrect b. a mutation in the gene controlling the timing of flowering. Incorrect c. behavioral isolation. Incorrect d. polyploidy. Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to Choose one answer. a. reduce the number of flies that you transfer at each generation. Incorrect b. shock the flies with a brief treatment of heat or cold to make them more hardy. Incorrect c. cross your flies with flies from another lab. Correct d. transfer only the largest flies. Incorrect e. change the temperature at which you rear the flies. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? Choose one answer. a. Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. Incorrect b. The double bonds block interaction among the hydrophilic head groups of the lipids. Incorrect c. The double bonds result in shorter fatty acid tails and thinner membranes. Incorrect d. Unsaturated fatty acids permit more water in the interior of the membrane. Incorrect e. The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. Correct Correct Marks for this submission: 1/1. Question 56 Marks: 1 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. photosynthesis. Incorrect b. both photosynthesis and respiration. Incorrect c. respiration. Incorrect d. neither photosynthesis nor respiration. Correct e. photorespiration. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following is an advantage of a complete digestive system over a gastrovascular cavity? Choose one answer. a. Specialized regions are possible. Correct b. Extensive branching is possible. Incorrect c. Extracellular digestion is not needed. Incorrect d. Intracellular digestion is easier. Incorrect e. Digestive enzymes can be more specific. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? Choose one answer. a. MPF Incorrect b. cyclin Correct c. PDGF Incorrect d. Cdk Incorrect e. protein kinase Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect b. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct c. There is no relationship between the light reactions and the Calvin cycle. Incorrect d. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect e. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 To leave the digestive tract, a substance must cross a cell membrane. During which stage of food processing does this take place? Choose one answer. a. hydrolysis Incorrect b. ingestion Incorrect c. digestion Incorrect d. elimination Incorrect e. absorption Correct Correct Marks for this submission: 1/1. 9 Weeks Exam Practice Review of Attempt 9 Started on Saturday, January 17, 2009, 08:40 AM Completed on Saturday, January 17, 2009, 08:41 AM Time taken 1 min 55 secs Raw score 8/60 (13%) Grade out of a maximum of Question 1 Marks: 1 How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? Choose one answer. a. 64 Incorrect b. 16 Incorrect c. 4 Incorrect d. 8 Correct e. 32 Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which of these individuals is most likely to be successful in an evolutionary sense? Choose one answer. a. a male who mates with 20 females and fathers 1 offspring Incorrect b. an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce Correct c. an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce Incorrect d. a female who mates with 20 males and produces 1 offspring Incorrect e. a reproductively sterile individual who never falls ill Incorrect Correct Marks for this submission: 1/1. Question 3 Marks: 1 Which of the following describes ubiquinone? Choose one answer. a. a protein in the electron transport chain Incorrect b. an essential amino acid Incorrect c. a substrate for synthesis of FADH Incorrect d. a small hydrophobic coenzyme Correct e. a vitamin needed for efficient glycolysis Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The body fluids of an osmoconformer would be __________ with its __________ environment. Choose one answer. a. hypoosmotic; saltwater Incorrect b. isoosmotic; saltwater Correct c. hyperosmotic; saltwater Incorrect d. hyperosmotic; freshwater Incorrect e. isotonic; freshwater Incorrect Correct Marks for this submission: 1/1. Question 5 Marks: 1 If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the Choose one answer. a. lack of genetic variation among all members of a population. Incorrect b. unlimited resources that support population growth in most natural environments. Incorrect c. ability of populations to undergo modification as they adapt to a particular environment. Correct d. relative stability of a well-adapted population's numbers over many generations. Incorrect e. tendency of organisms to produce the exact number of offspring that the environment can support. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur? Choose one answer. a. The potential energy of the electron has to go back to the ground state. Incorrect b. These chlorophyll a molecules are associated with higher concentrations of ATP. Incorrect c. The molecular environment lets it boost an electron to a higher energy level and also to transfer the electron to another molecule. Correct d. Each pigment molecule has to be able to act independently to excite electrons. Incorrect e. The action spectrum of that molecule is such that it is different from other molecules of chlorophyll. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following is true for all exergonic reactions? Choose one answer. a. Some reactants will be converted to products. Incorrect b. The products have more total energy than the reactants. Incorrect c. The reactions are nonspontaneous. Incorrect d. The reaction proceeds with a net release of free energy. Correct e. A net input of energy from the surroundings is required for the reactions to proceed. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur? Choose one answer. a. The ATP must first have to attach to the tRNA. Incorrect b. The tRNA molecule must have to alter its shape in order to be able to fit into the active site with the other two molecules. Incorrect c. The 3' end of the tRNA must have to be cleaved before it can have an attached amino acid. Incorrect d. The hydrolysis of the ATP must be needed to allow the amino acid to bind to the synthetase. Incorrect e. The binding of the first two molecules must cause a 3-dimensional change that opens another active site on the enzyme. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 What part(s) of the digestive system have secretions with a pH of 2? Choose one answer. a. mouth Incorrect b. pancreas Incorrect c. small intestine Incorrect d. stomach Correct e. liver Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which two functional groups are always found in amino acids? Choose one answer. a. ketone and aldehyde Incorrect b. hydroxyl and aldehyde Incorrect c. carbonyl and carboxyl Incorrect d. phosphate and sulfhydryl Incorrect e. carboxyl and amino Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 When pairs of homologous chromosomes separate during anaphase I, Choose one answer. a. the sister chromatids remain attached to one another. Correct b. the synaptonemal complex is visible under the light microscope. Incorrect c. the maternal chromosomes all move to the same daughter cell. Incorrect d. recombination is not yet complete. Incorrect Correct Marks for this submission: 1/1. Question 12 Marks: 1 A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? Choose one answer. a. 63 chromosomes, each with three chromatids Incorrect b. 63 chromosomes in 31 1/2 pairs Incorrect c. 63 chromosomes in 21 sets of 3 Correct d. 21 chromosome pairs and 21 unique chromosomes Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it? Choose one answer. a. allopatric speciation, behavioral isolation Incorrect b. sympatric speciation, sexual selection Incorrect c. allopatric speciation, ecological isolation Incorrect d. sympatric speciation, allopolyploidy Incorrect e. sympatric speciation, habitat differentiation Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is a hydrophobic material? Choose one answer. a. table salt Incorrect b. paper Incorrect c. sugar Incorrect d. wax Correct e. pasta Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of these often serve as receptors or cell recognition molecules on cell surfaces? Choose one answer. a. transmembrane proteins Incorrect b. integrins Incorrect c. glycoproteins Correct d. integral proteins Incorrect e. peripheral proteins Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 An electron loses potential energy when it Choose one answer. a. attaches itself to NAD+. Incorrect b. increases its activity as an oxidizing agent. Incorrect c. shifts to a less electronegative atom. Incorrect d. shifts to a more electronegative atom. Correct e. increases its kinetic energy. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are Choose one answer. a. carbohydrates. Incorrect b. peripheral proteins. Incorrect c. phospholipids. Incorrect d. cholesterol molecules. Incorrect e. integral proteins. Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility, and death, usually of coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption? Choose one answer. a. Successive generations of a family will continue to have more and more cases over time. Incorrect b. Each patient will have had at least one affected family member in a previous generation. Incorrect c. The disease is autosomal dominant. Incorrect d. The disorder may be due to mutation in a single protein-coding gene. Correct e. All cases must occur in relatives; therefore, there must be only one mutant allele. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a marine bony fish Correct b. a shark inhabiting freshwater Lake Nicaragua Incorrect c. a freshwater bony fish Incorrect d. a salmon in freshwater Incorrect e. a marine shark Incorrect Correct Marks for this submission: 1/1. Question 20 Marks: 1 Which is a general term for enzymes that activate or inactivate other proteins by phosphorylating them? Choose one answer. a. PDGF Incorrect b. MPF Incorrect c. cyclin Incorrect d. Cdk Incorrect e. protein kinase Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which sequence of blood flow can be observed in either a reptile or a mammal? Choose one answer. a. left ventricle ? aorta ? lungs ? systemic circulation Incorrect b. pulmonary vein ? left atrium ? ventricle ? pulmonary circuit Incorrect c. vena cava ? right atrium ? ventricle ? pulmonary circuit Correct d. right ventricle ? pulmonary vein ? pulmocutaneous circulation Incorrect e. right atrium ? pulmonary artery ? left atrium ? ventricle Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? Choose one answer. a. 55.6M Correct b. 18M Incorrect c. 1.0M Incorrect d. 37M Incorrect e. 0.66M Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Natural selection changes allele frequencies in populations because some __________ survive and reproduce more successfully than others. Choose one answer. a. alleles Incorrect b. individuals Correct c. gene pools Incorrect d. species Incorrect e. loci Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect b. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect c. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct d. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect e. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? Choose one answer. a. anaphase Incorrect b. metaphase Correct c. telophase Incorrect d. interphase Incorrect e. prophase Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. frog Correct b. fish Incorrect c. insect Incorrect d. mollusc Incorrect e. annelid Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 In which blood vessel is glucose concentration likely to vary the most? Choose one answer. a. pulmonary veins Incorrect b. abdominal artery Incorrect c. hepatic portal vessel Correct d. hepatic vein, which drains the liver Incorrect e. coronary arteries Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Where are the molecules of the electron transport chain found in plant cells? Choose one answer. a. inner membrane of mitochondria Incorrect b. thylakoid membranes of chloroplasts Correct c. matrix of mitochondria Incorrect d. cytoplasm Incorrect e. stroma of chloroplasts Incorrect Correct Marks for this submission: 1/1. Question 29 Marks: 1 Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. a. ATP is phosphorylated to yield ADP. Incorrect b. NADP is produced. Incorrect c. carbon dioxide is incorporated into PGA. Incorrect d. light is absorbed and funneled to reaction-center chlorophyll a. Correct e. NADPH is reduced to NADP+. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 The high osmolarity of the renal medulla is maintained by all of the following except Choose one answer. a. active transport of salt from the upper region of the ascending limb. Incorrect b. diffusion of urea from the collecting duct. Incorrect c. the spatial arrangement of juxtamedullary nephrons. Incorrect d. diffusion of salt from the thin segment of the ascending limb of the loop of Henle. Incorrect e. diffusion of salt from the descending limb of the loop of Henle. Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 What is a hypothesis? Choose one answer. a. a fact based on qualitative data that is testable Incorrect b. a tentative explanation that can be tested and is falsifiable Correct c. a fact based on quantitative data that is falsifiable Incorrect d. the same thing as an unproven theory Incorrect e. a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Reduction of NADP+ occurs during Choose one answer. a. both photosynthesis and respiration. Incorrect b. photosynthesis. Correct c. photorespiration. Incorrect d. neither photosynthesis nor respiration. Incorrect e. respiration. Incorrect Correct Marks for this submission: 1/1. Question 33 Marks: 1 The sugar that results from three "turns" of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this? Choose one answer. a. Formation of a molecule of glucose would require 9 "turns." Incorrect b. The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements. Correct c. G3P is easier for a plant to store. Incorrect d. Some plants would not taste sweet to us. Incorrect e. G3P more readily forms sucrose and other disaccharides than it does monosaccharides. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Pulse is a direct measure of Choose one answer. a. breathing rate. Incorrect b. blood pressure. Incorrect c. stroke volume. Incorrect d. heart rate. Correct e. cardiac output. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 A controlled experiment is one that Choose one answer. a. is repeated many times to make sure the results are accurate. Incorrect b. keeps all environmental variables constant. Incorrect c. proceeds slowly enough that a scientist can make careful records of the results. Incorrect d. may include experimental groups and control groups tested in parallel. Correct e. is supervised by an experienced scientist. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The conversion of fibrinogen to fibrin Choose one answer. a. is linked to hypertension and may damage artery walls. Incorrect b. occurs within red blood cells. Incorrect c. is likely to occur too often in an individual with hemophilia. Incorrect d. is the final step of a clotting process that involves multiple clotting factors. Correct e. occurs when fibrinogen is released from broken platelets. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. water. Incorrect b. sugar. Incorrect c. starch. Incorrect d. protein. Incorrect e. fat. Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The plant's height is 25 centimeters (cm). Incorrect b. The temperature decreased from 20°C to 15°C. Incorrect c. The contents of the stomach are mixed every 20 seconds. Incorrect d. The fish swam in a zig-zag motion. Correct e. The six pairs of robins hatched an average of three chicks. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 As a young biologist, Charles Darwin had expected the living plants of temperate South America would resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explanation for this observation is most properly associated with the field of Choose one answer. a. embryology. Incorrect b. meteorology. Incorrect c. vertebrate anatomy. Incorrect d. bioengineering. Incorrect e. biogeography. Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They can have very long carbon skeletons. Incorrect b. They have a lot of electrons associated with hydrogen. Correct c. They are easily reduced. Incorrect d. They have a lot of oxygen atoms. Incorrect e. They have no nitrogen in their makeup. Incorrect Correct Marks for this submission: 1/1. Question 41 Marks: 1 Which term describes centrioles beginning to move apart in animal cells? Choose one answer. a. metaphase Incorrect b. telophase Incorrect c. anaphase Incorrect d. prometaphase Incorrect e. prophase Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 What is the source of the extra chromosome 21 in an individual with Down syndrome? Choose one answer. a. Duplication of the chromosome Incorrect b. It is impossible to detect with current technology Incorrect c. Nondisjunction in the mother only Incorrect d. Nondisjunction in the father only Incorrect e. Nondisjunction or translocation in either parent Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The experimental approach taken in current biological investigations presumes that Choose one answer. a. a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods. Incorrect b. living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena. Correct c. simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms. Incorrect d. although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods. Incorrect e. living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? Choose one answer. a. n + 1; n + 1; n; n Incorrect b. n + 1; n - 1; n - 1; n - 1 Incorrect c. n - 1; n - 1; n; n Incorrect d. n + 1; n + 1; n - 1; n - 1 Correct e. n + 1; n - 1; n; n Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. disaccharides Incorrect b. enzymes Incorrect c. monomers Correct d. polymers Incorrect e. peptides Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 The active site of an enzyme is the region that Choose one answer. a. is inhibited by the presence of a coenzyme or a cofactor. Incorrect b. is involved in the catalytic reaction of the enzyme. Correct c. binds the products of the catalytic reaction. Incorrect d. binds allosteric regulators of the enzyme. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Given the parents AABBCc × AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent? Choose one answer. a. 1 Incorrect b. 1/8 Incorrect c. 3/8 Incorrect d. 3/4 Correct e. 1/4 Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The ATP made during glycolysis is generated by Choose one answer. a. chemiosmosis. Incorrect b. photophosphorylation. Incorrect c. electron transport. Incorrect d. substrate-level phosphorylation. Correct e. oxidation of NADH to NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide would be found within the Choose one answer. a. ribosomes. Incorrect b. endoplasmic reticulum. Incorrect c. mitochondria. Correct d. peroxisomes. Incorrect e. lysosomes. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following is a false statement concerning amino groups? Choose one answer. a. They are components of urea. Incorrect b. They are found in amino acids. Incorrect c. They are basic in pH. Incorrect d. They are nonpolar. Correct e. They contain nitrogen. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. ammonia Incorrect b. urea Incorrect c. nitrite Incorrect d. nitrate Incorrect e. uric acid Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following factors would tend to increase membrane fluidity? Choose one answer. a. a relatively high protein content in the membrane Incorrect b. a greater proportion of unsaturated phospholipids Correct c. a greater proportion of saturated phospholipids Incorrect d. a lower temperature Incorrect e. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses Incorrect Correct Marks for this submission: 1/1. Question 53 Marks: 1 How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? Choose one answer. a. by binding at the active site of the enzyme Incorrect b. by acting as a coenzyme for the reaction Incorrect c. by decreasing the activation energy of the reaction Incorrect d. by changing the free energy change of the reaction Incorrect e. by changing the shape of a reactant Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is Choose one answer. a. transferred to ADP, forming ATP. Incorrect b. transferred directly to ATP. Incorrect c. stored in the NADH produced. Incorrect d. used to phosphorylate fructose to form fructose-6-phosphate. Incorrect e. retained in the pyruvate. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform successful meiosis. Consequently, which statement about mules is true? Choose one answer. a. When two mules interbreed, genetic recombination cannot occur by meiotic crossing over, but only by the act of fertilization. Incorrect b. Their offspring have less genetic variation than the parents. Incorrect c. They have a relative evolutionary fitness of zero. Correct d. If crossing-over happens in mules, then it must be limited to prophase of mitosis. Incorrect e. Mutations cannot occur in their genomes. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 What would account for increased urine production as a result of drinking alcoholic beverages? Choose one answer. a. increased aldosterone production Incorrect b. inhibition of antidiuretic hormone secretion (ADH) Correct c. increased reabsorption of water in the proximal tubule Incorrect d. increased blood pressure Incorrect e. the osmoregulator cells of the brain increasing their activity Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct b. bringing glucose and fructose together to form sucrose. Incorrect c. production of water from the sugar as bonds are broken between the glucose monomers. Incorrect d. the release of water from sucrose as the bond between glucose and fructose is broken. Incorrect e. utilization of water as a covalent bond is formed between glucose and fructose to form sucrase. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 In which group of animals would you expect to find a relatively long cecum? Choose one answer. a. autotrophs Incorrect b. omnivores Incorrect c. heterotrophs Incorrect d. herbivores Correct e. carnivores Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 A mycoplasma is an organism with a diameter between 0.1 and 1.0 µm. What does its size tell you about how it might be classified? Choose one answer. a. It must be a single celled fungus. Incorrect b. It could be almost any typical bacterium. Incorrect c. It could be a typical virus. Incorrect d. It must be a single celled protist. Incorrect e. It could be a very small bacterium. Correct Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? Choose one answer. a. Animalia Incorrect b. Protista Incorrect c. Eukarya Incorrect d. Archaea Correct e. Fungi Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 1 Started on Saturday, January 17, 2009, 09:43 AM Completed on Saturday, January 17, 2009, 09:43 AM Time taken 14 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Damage to the sinoatrial node in humans Choose one answer. a. is a major contributor to heart attacks. Incorrect b. would have a direct effect on blood pressure monitors in the aorta. Incorrect c. would have a negative effect on peripheral resistance. Incorrect d. would block conductance between the bundle branches and the Purkinje fibers. Incorrect e. would disrupt the rate and timing of cardiac muscle contractions. Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which of the following respiratory systems is not closely associated with a blood supply? Choose one answer. a. the tracheal system of an insect Correct b. the lungs of a vertebrate Incorrect c. the skin of an earthworm Incorrect d. the gills of a fish Incorrect e. the parapodia of a polychaete worm Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual? Choose one answer. a. 47, XXY Incorrect b. 45, X Incorrect c. 47, XYY Incorrect d. 47, XXX Incorrect e. 47, +21 Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? Choose one answer. a. stabilizing selection Correct b. sexual selection Incorrect c. artificial selection Incorrect d. directional selection Incorrect e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect b. protein function at one site affected by binding at another of its active sites Incorrect c. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect d. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct e. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 How does ADH function at the cellular level? Choose one answer. a. It causes membranes to include more phospholipids that have unsaturated fatty acids. Incorrect b. It causes an increase in the number of aquaporin molecules of collecting duct cells. Correct c. ADH stimulates the reabsorption of glucose through channel proteins. Incorrect d. It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water. Incorrect e. It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 It has been found that certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This is evidence in support of the claim that Choose one answer. a. natural selection can produce new structures by cobbling together parts of other structures. Correct b. some structures are so complex that natural selection cannot, and will not, explain their origins. Incorrect c. the motors of bacterial flagella were originally synthesized abiotically. Incorrect d. bacteria that possess flagella must have lost the ability to pump certain chemicals across their plasma membranes. Incorrect e. the power of natural selection allows it to act in an almost predictive fashion, producing organs that will be needed in future environments. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The sugar that results from three "turns" of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this? Choose one answer. a. The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements. Correct b. G3P is easier for a plant to store. Incorrect c. Some plants would not taste sweet to us. Incorrect d. G3P more readily forms sucrose and other disaccharides than it does monosaccharides. Incorrect e. Formation of a molecule of glucose would require 9 "turns." Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. a food molecule made up of energy-rich macromolecules Correct b. an insect foraging for food Incorrect c. water rushing over Niagara Falls Incorrect d. a boy mowing grass Incorrect e. a firefly using light flashes to attract a mate Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following enzymes works most effectively at a very low pH? Choose one answer. a. pancreatic amylase Incorrect b. trypsin Incorrect c. pancreatic lipase Incorrect d. pepsin Correct e. salivary amylase Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is (are) true for anabolic pathways? Choose one answer. a. They do not depend on enzymes. Incorrect b. They consume energy to build up polymers from monomers. Correct c. They release energy as they degrade polymers to monomers. Incorrect d. They are usually highly spontaneous chemical reactions. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following vitamins is correctly associated with its use? Choose one answer. a. vitamin Eprotection of skin from cancer Incorrect b. vitamin Aincorporated into the visual pigment of the eye Correct c. vitamin Kproduction of white blood cells Incorrect d. vitamin Ccuring rickets Incorrect e. vitamin Dcalcium removal from bone Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? Choose one answer. a. 100 mL of tomato juice Incorrect b. 100 mL of freshly-brewed coffee Incorrect c. 100 mL of freshly-squeezed orange juice Incorrect d. 100 mL of household cleanser containing 0.5M ammonia Correct e. 100 mL of pure water Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic respiration? Choose one answer. a. on the inner plasma membrane Correct b. on the endoplasmic reticulum Incorrect c. on the inner nuclear envelope Incorrect d. in the cytoplasm Incorrect e. on the inner mitochondrial membrane Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 An electron loses potential energy when it Choose one answer. a. increases its activity as an oxidizing agent. Incorrect b. shifts to a more electronegative atom. Correct c. shifts to a less electronegative atom. Incorrect d. increases its kinetic energy. Incorrect e. attaches itself to NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? Choose one answer. a. 32 Correct b. 64 Incorrect c. 4 Incorrect d. 16 Incorrect e. 8 Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. a. harvest photons and transfer light energy to the reaction-center chlorophyll Correct b. synthesize ATP from ADP and Pi Incorrect c. concentrate photons within the stroma Incorrect d. split water and release oxygen to the reaction-center chlorophyll Incorrect e. transfer electrons to ferredoxin and then NADPH Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Prokaryotes are classified as belonging to two different domains. What are the domains? Choose one answer. a. Bacteria and Protista Incorrect b. Eukarya and Monera Incorrect c. Bacteria and Archaea Correct d. Archaea and Monera Incorrect e. Bacteria and Eukarya Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in Choose one answer. a. anaphase. Incorrect b. prophase. Incorrect c. G2. Incorrect d. metaphase. Incorrect e. G1 Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. prophase Incorrect b. telophase Incorrect c. anaphase Incorrect d. prometaphase Incorrect e. metaphase Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which of the following statements correctly describes some aspect of protein disposal from prokaryotic cells? Choose one answer. a. Prokaryotes contain large pores in their plasma membrane that permit the movement of proteins out of the cell. Incorrect b. Proteins that are excreted by prokaryotes are synthesized on ribosomes that are bound to the cytoplasmic surface of the plasma membrane. Correct c. Prokaryotes are unlikely to be able to excrete proteins because they lack an endomembrane system. Incorrect d. The mechanism of protein excretion in prokaryotes is probably the same as that in eukaryotes. Incorrect e. In prokaryotes, the ribosomes that are used for the synthesis of secreted proteins are located outside of the cell. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 What is the hydroxide ion concentration of the lake described in question 7? Choose one answer. a. 10-10M Correct b. 10-4M Incorrect c. 10-14 M Incorrect d. 10-7M Incorrect e. 10 M Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Cellular respiration harvests the most chemical energy from which of the following? Choose one answer. a. converting oxygen to ATP Incorrect b. chemiosmotic phosphorylation Correct c. generating carbon dioxide and oxygen in the electron transport chain Incorrect d. transferring electrons from organic molecules to pyruvate Incorrect e. substrate-level phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 In hypothesis-based science, deductive reasoning is used to predict a result that would be found if a particular hypothesis is correct. Answer: True False Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? Choose one answer. a. Living organisms are able to transform energy into entropy. Incorrect b. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe. Incorrect c. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth. Correct d. Living organisms do not follow the laws of thermodynamics. Incorrect e. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 The pH of the gastric juice of the stomach is about 2 due to the formation of HCl. Where does this formation of HCl occur? Choose one answer. a. in the lumen of the stomach Correct b. in the secretions of the esophagus Incorrect c. in the parietal cells of the stomach Incorrect d. in the chief cells of the stomach Incorrect e. in the transformation of pepsinogen to pepsin Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 A Barr body is normally found in the nucleus of which kind of human cell? Choose one answer. a. Somatic cells of a female only Correct b. Sperm cells only Incorrect c. Both male and female somatic cells Incorrect d. Somatic cells of a male only Incorrect e. Unfertilized egg cells only Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which of the following is true of the evolution of cell membranes? Choose one answer. a. Cell membranes cannot evolve if proteins do not. Incorrect b. Cell membranes have stopped evolving now that they are fluid mosaics. Incorrect c. As populations of organisms evolve, different properties of their cell membranes are selected for or against. Correct d. An individual organism selects its preferred type of cell membrane for particular functions. Incorrect e. The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of these individuals is most likely to be successful in an evolutionary sense? Choose one answer. a. an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce Incorrect b. a reproductively sterile individual who never falls ill Incorrect c. a male who mates with 20 females and fathers 1 offspring Incorrect d. a female who mates with 20 males and produces 1 offspring Incorrect e. an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the following would be described as a portal system? Choose one answer. a. a space within or between organs where blood is allowed to pool Incorrect b. a slightly muscular vessel that has minimal pumping action in an organism with no heart Incorrect c. a series of vessels that returns blood to the heart in an animal with an open circulatory system Incorrect d. an area connecting arterioles to venules Incorrect e. a vessel or vessels connecting two capillary beds Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? Choose one answer. a. morphological Correct b. phylogenetic Incorrect c. biological Incorrect d. ecological Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? Choose one answer. a. 760 mm Hg Incorrect b. 80 mm Hg Correct c. 380 mm Hg Incorrect d. 0 mm Hg Incorrect e. 160 mm Hg Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Organisms categorized as osmoconformers are most likely Choose one answer. a. found in fresh water lakes and streams. Incorrect b. found in arid terrestrial environments. Incorrect c. amphibious. Incorrect d. marine. Correct e. found in terrestrial environments with adequate moisture. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. NADH Incorrect b. ATP Incorrect c. ADP + Pi Incorrect d. FADH2 Correct e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following is true regarding saturated fatty acids? Choose one answer. a. They are usually produced by plants. Incorrect b. They are usually liquid at room temperature. Incorrect c. They are the principal molecules in lard and butter. Correct d. They have double bonds between carbon atoms of the fatty acids. Incorrect e. They are the predominant fatty acid in corn oil. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. reduce FADH2 to FAD+. Incorrect b. reduce FAD+ to FADH2. Incorrect c. reduce NAD+ to NADH. Incorrect d. none of the above Incorrect e. oxidize NADH to NAD+. Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which one of the following, if present in a urine sample, would likely be caused by trauma? Choose one answer. a. amino acids Incorrect b. vitamins Incorrect c. salts Incorrect d. glucose Incorrect e. erythrocytes Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to Choose one answer. a. suppression of cyclin production. Incorrect b. inhibition of DNA synthesis. Incorrect c. myosin denaturation and inhibition of cleavage furrow formation. Incorrect d. inhibition of regulatory protein phosphorylation. Incorrect e. disruption of mitotic spindle formation. Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? Choose one answer. a. protein kinase Incorrect b. PDGF Incorrect c. MPF Incorrect d. cyclin Correct e. Cdk Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will Choose one answer. a. rapidly increase. Incorrect b. remain unchanged. Incorrect c. rapidly decline. Incorrect d. gradually decline. Correct e. gradually increase. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Charles Darwin proposed a mechanism for descent with modification which stated that organisms of a particular species are adapted to their environment when they possess Choose one answer. a. inheritable traits that enhance their survival and reproductive success in the local environment. Correct b. non-inheritable traits that enhance their survival in the local environment. Incorrect c. non-inheritable traits that enhance their reproductive success in the local environment. Incorrect d. inheritable traits that decrease their survival and reproductive success in the local environment. Incorrect e. non-inheritable traits that enhance their survival and reproductive success in the local environment. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which type of bond must be broken for water to vaporize? Choose one answer. a. polar covalent bonds Incorrect b. nonpolar covalent bonds Incorrect c. covalent bonds Incorrect d. hydrogen bonds Correct e. ionic bonds Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 In mechanism, photophosphorylation is most similar to Choose one answer. a. carbon fixation. Incorrect b. the Calvin cycle. Incorrect c. reduction of NADP+. Incorrect d. oxidative phosphorylation in cellular respiration. Correct e. substrate-level phosphorylation in glycolysis. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Why are C4 plants able to photosynthesize with no apparent photorespiration? Choose one answer. a. They are adapted to cold, wet climates. Incorrect b. They use PEP carboxylase to initially fix CO2. Correct c. They conserve water more efficiently. Incorrect d. They exclude oxygen from their tissues. Incorrect e. They do not participate in the Calvin cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of these conditions should completely prevent the occurrence of natural selection in a population over time? Choose one answer. a. The population size is large. Incorrect b. All variation between individuals is due only to environmental factors. Correct c. The environment is changing at a relatively slow rate. Incorrect d. The population lives in a habitat where there are no competing species present. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following statements best describes the relationship between photosynthesis and respiration? Choose one answer. a. ATP molecules are produced in photosynthesis and used up in respiration. Incorrect b. Photosynthesis occurs only in plants and respiration occurs only in animals. Incorrect c. Respiration is anabolic and photosynthesis is catabolic. Incorrect d. Photosynthesis stores energy in complex organic molecules, while respiration releases it. Correct e. Respiration is the reversal of the biochemical pathways of photosynthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following span the phospholipids bilayer, usually a number of times? Choose one answer. a. integrins Incorrect b. integral proteins Incorrect c. peripheral proteins Incorrect d. transmembrane proteins Correct e. glycoproteins Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. an artery Correct b. a portal vessel Incorrect c. a capillary Incorrect d. a venule Incorrect e. a vein Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 A biologist is studying kidney tubules in small mammals. She wants specifically to examine the juxtaposition of different types of cells in these structures. The cells in question can be distinguished by external shape, size, and 3-dimensional characteristics. Which would be the optimum method for her study? Choose one answer. a. transmission electron microscopy Incorrect b. scanning electron microscopy Correct c. light microscopy using stains specific to kidney function Incorrect d. light microscopy using living unstained material Incorrect e. cell fractionation Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility, and death, usually of coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption? Choose one answer. a. Each patient will have had at least one affected family member in a previous generation. Incorrect b. All cases must occur in relatives; therefore, there must be only one mutant allele. Incorrect c. The disease is autosomal dominant. Incorrect d. Successive generations of a family will continue to have more and more cases over time. Incorrect e. The disorder may be due to mutation in a single protein-coding gene. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality could allow which of the following to have a male phenotype? Choose one answer. a. Down syndrome, 46, XX Incorrect b. Translocation of SRY to an autosome of a 46, XX individual Correct c. A person with too many X chromosomes Incorrect d. Turner syndrome, 45, X Incorrect e. A person with one normal and one shortened (deleted) X Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following is an example of hydrolysis? Choose one answer. a. the reaction of a fat, forming glycerol and fatty acids with the utilization of water Correct b. the reaction of two monosaccharides, forming a disaccharide with the release of water Incorrect c. the reaction of a fat, forming glycerol and fatty acids with the release of water Incorrect d. the synthesis of two amino acids, forming a peptide with the release of water Incorrect e. the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? Choose one answer. a. remove oxygen from lactate Incorrect b. remove lactate from the blood Incorrect c. transform lactate to pyruvate again Incorrect d. continue aerobic metabolism when skeletal muscle cannot Correct e. derive sufficient energy from fermentation Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the following is considered an open system? Choose one answer. a. food cooking in a pressure cooker Incorrect b. a sealed terrarium Incorrect c. an organism Correct d. liquid in a corked bottle Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following processes of osmoregulation by the kidney is the least selective? Choose one answer. a. filtration Correct b. secretion Incorrect c. H+ pumping to control pH Incorrect d. reabsorption Incorrect e. salt pumping to control osmolarity Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Natural selection is based on all of the following except Choose one answer. a. genetic variation exists within populations. Incorrect b. individuals adapt to their environments and, thereby, evolve. Correct c. the best-adapted individuals tend to leave the most offspring. Incorrect d. populations tend to produce more individuals than the environment can support. Incorrect e. individuals who survive longer tend to leave more offspring than those who die young. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. high level of secretion from parietal cells Incorrect b. a sufficient colony of H. pylori Incorrect c. secretions entering the stomach from the pancreas Incorrect d. high level of secretion by chief cells Incorrect e. mucus secretion and active mitosis of epithelial cells Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. peptides Incorrect b. polymers Incorrect c. enzymes Incorrect d. disaccharides Incorrect e. monomers Correct Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following is true of urea? It is Choose one answer. a. the primary nitrogenous waste product of most birds. Incorrect b. the primary nitrogenous waste product of most aquatic invertebrates. Incorrect c. more toxic to human cells than ammonia. Incorrect d. the primary nitrogenous waste product of humans. Correct e. insoluble in water. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that Choose one answer. a. many of the observable characters that vary in pea plants are controlled by single genes. Incorrect b. it is possible to control matings between different pea plants. Incorrect c. peas have an unusually long generation time. Correct d. peas show easily observed variations in a number of characters, such as pea shape and flower color. Incorrect e. it is possible to obtain large numbers of progeny from any given cross. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 2 Started on Saturday, January 17, 2009, 09:54 AM Completed on Saturday, January 17, 2009, 09:54 AM Time taken 8 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will Choose one answer. a. rapidly increase. Incorrect b. gradually decline. Correct c. gradually increase. Incorrect d. remain unchanged. Incorrect e. rapidly decline. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. starch. Incorrect b. sugar. Incorrect c. fat. Correct d. water. Incorrect e. protein. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. a. fatty acids and glycerol. Incorrect b. phospholipids and glycolipids. Incorrect c. starch and cellulose. Incorrect d. proteins and nucleic acids. Correct e. triglycerides and steroids. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? Choose one answer. a. all ducts, such as those from salivary or sebaceous glands Incorrect b. egg cells (ova), uterus, and kidneys Incorrect c. limbs, hearts, areas with a good deal of contraction Incorrect d. sperm, larynx, and trachea Correct e. microvilli, alveoli, and glomeruli Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Some bacteria are metabolically active in hot springs because Choose one answer. a. they use molecules other than proteins or RNAs as their main catalysts. Incorrect b. they are able to maintain a cooler internal temperature. Incorrect c. high temperatures make catalysis unnecessary. Incorrect d. their enzymes have high optimal temperatures. Correct e. their enzymes are completely insensitive to temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which statement describes the functioning of photosystem II? Choose one answer. a. The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit. Incorrect b. The splitting of water yields molecular carbon dioxide as a by-product. Incorrect c. Light energy excites electrons in the electron transport chain in a photosynthetic unit. Incorrect d. The electron vacancies in P680 are filled by electrons derived from water. Correct e. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which process is most directly driven by light energy? Choose one answer. a. reduction of NADP+ molecules Incorrect b. ATP synthesis Incorrect c. removal of electrons from chlorophyll molecules Correct d. carbon fixation in the stroma Incorrect e. creation of a pH gradient by pumping protons across the thylakoid membrane Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA? Choose one answer. a. S Incorrect b. G1 Incorrect c. M Incorrect d. G2 Correct e. G0 Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following mechanisms for osmoregulation or nitrogen removal is correctly paired with its corresponding animal? Choose one answer. a. Malpighian tubule-frog Incorrect b. direct cellular exchange-marine invertebrate Correct c. metanephridium-flatworm Incorrect d. kidney-insect Incorrect e. flame bulb-snake Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. glycolysis and fermentation Correct b. oxidation of pyruvate to acetyl CoA Incorrect c. oxidative phosphorylation Incorrect d. citric acid cycle Incorrect e. fermentation and chemiosmosis Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________. Choose one answer. a. producers; consumers Incorrect b. plants; heat Incorrect c. sunlight; heat Correct d. heat; light Incorrect e. plants; animals Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called Choose one answer. a. centrioles. Incorrect b. proton pumps. Incorrect c. ATPases. Incorrect d. kinetochores. Incorrect e. cyclins. Correct Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose? Choose one answer. a. 24 Incorrect b. 6.02 × 1023 Correct c. 180 × 1014 Incorrect d. 23 × 1014 Incorrect e. 342 Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is a hydrophobic material? Choose one answer. a. paper Incorrect b. table salt Incorrect c. sugar Incorrect d. wax Correct e. pasta Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? Choose one answer. a. Cancer cells are no longer anchorage dependent. Incorrect b. Chromosomally abnormal cells still have normal metabolism. Incorrect c. Cancer cells are no longer density dependent. Incorrect d. Transformation introduces new chromosomes into cells. Incorrect e. Chromosomally abnormal cells can still go through cell cycle checkpoints. Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following is true of metabolism in its entirety? Choose one answer. a. Metabolism utilizes all of an organism's resources Incorrect b. Metabolism is a property of organismal life Correct c. Metabolism manages the increase of entropy in an organism Incorrect d. Metabolism depends on an organism's adequate hydration Incorrect e. Metabolism depends on a constant supply of energy from food Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H12O6) in cellular respiration? Choose one answer. a. 38 Incorrect b. 2 Incorrect c. 76 Correct d. 4 Incorrect e. 15 Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 The meshwork that forms the fabric of a blood clot consists mostly of which protein? Choose one answer. a. fibrin Correct b. fibrinogen Incorrect c. thrombin Incorrect d. collagen Incorrect e. prothrombin Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following is a compartment that often takes up much of the volume of a plant cell? Choose one answer. a. vacuole Correct b. lysosome Incorrect c. mitochondrion Incorrect d. peroxisome Incorrect e. Golgi apparatus Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which of the following describes peristalsis in the digestive system? Choose one answer. a. voluntary control of the rectal sphincters regulating defecation Incorrect b. the transport of nutrients to the liver through the hepatic portal vessel Incorrect c. a process of fat emulsification in the small intestine Incorrect d. smooth muscle contractions that move food through the alimentary canal Correct e. a common cause of loss of appetite, fatigue, and dehydration Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have which of the following? Choose one answer. a. an open circulatory system Incorrect b. hemolymph Incorrect c. branched tracheae Incorrect d. a closed circulatory system Correct e. a gastrovascular cavity Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 In order for anaphase to begin, which of the following must occur? Choose one answer. a. Spindle microtubules must begin to depolymerize. Incorrect b. Kinetochores must attach to the metaphase plate. Incorrect c. Chromatids must lose their kinetochores. Incorrect d. Cohesin must be cleaved enzymatically. Correct e. Cohesin must attach the sister chromatids to each other. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. a. ATP is phosphorylated to yield ADP. Incorrect b. light is absorbed and funneled to reaction-center chlorophyll a. Correct c. carbon dioxide is incorporated into PGA. Incorrect d. NADP is produced. Incorrect e. NADPH is reduced to NADP+. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways? Choose one answer. a. feedback regulation Incorrect b. bioenergetics Incorrect c. cooperativity Incorrect d. entropy Incorrect e. energy coupling Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? Choose one answer. a. Prophase I of meiosis Incorrect b. Anaphase I of meiosis Correct c. Metaphase I of meiosis Incorrect d. Anaphase of mitosis Incorrect e. Prophase II of meiosis Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 In alcohol fermentation, NAD+ is regenerated from NADH during which of the following? Choose one answer. a. reduction of acetaldehyde to ethanol (ethyl alcohol) Correct b. oxidation of pyruvate to acetyl CoA Incorrect c. oxidation of NAD+ in the citric acid cycle Incorrect d. reduction of pyruvate to form lactate Incorrect e. phosphorylation of ADP to form ATP Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Bacteria are beneficial to animal nutrition, including that of humans. Which of the following is among their greatest benefits to us? Choose one answer. a. recovery of water from fecal matter Incorrect b. generation of gases needed for elimination Incorrect c. absorption of organic materials Incorrect d. production of vitamins A and C Incorrect e. production of biotin and vitamin K Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which of the following minerals is associated with its use in animals? Choose one answer. a. calciumconstruction and maintenance of bone Correct b. ironnecessary for thyroid function Incorrect c. magnesiumcofactor in enzymes that make ATP Incorrect d. iodineimportant in nerve function Incorrect e. sulfuringredient of nucleic acids Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. fish Incorrect b. insect Incorrect c. mollusc Incorrect d. frog Correct e. annelid Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 It has been found that certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This is evidence in support of the claim that Choose one answer. a. bacteria that possess flagella must have lost the ability to pump certain chemicals across their plasma membranes. Incorrect b. some structures are so complex that natural selection cannot, and will not, explain their origins. Incorrect c. the motors of bacterial flagella were originally synthesized abiotically. Incorrect d. natural selection can produce new structures by cobbling together parts of other structures. Correct e. the power of natural selection allows it to act in an almost predictive fashion, producing organs that will be needed in future environments. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. a. brain, organ system, nerve cell, nervous tissue Incorrect b. nervous system, brain, nervous tissue, nerve cell Correct c. organ system, nervous tissue, brain Incorrect d. organ system, tissue, molecule, cell Incorrect e. organism, organ system, tissue, cell, organ Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a marine shark Incorrect b. a shark inhabiting freshwater Lake Nicaragua Incorrect c. a freshwater bony fish Incorrect d. a marine bony fish Correct e. a salmon in freshwater Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. metanephridia of earthworms Incorrect b. Malpighian tubules of insects Incorrect c. kidneys of vertebrates Correct d. protonephridia of rotifers Incorrect e. flame-bulb system of flatworms Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 The sugar that results from three "turns" of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this? Choose one answer. a. Some plants would not taste sweet to us. Incorrect b. G3P more readily forms sucrose and other disaccharides than it does monosaccharides. Incorrect c. Formation of a molecule of glucose would require 9 "turns." Incorrect d. G3P is easier for a plant to store. Incorrect e. The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements. Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called? Choose one answer. a. Deletion Incorrect b. Disjunction Incorrect c. Translocation Correct d. Inversion Incorrect e. Duplication Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? Choose one answer. a. as a pentose Incorrect b. as a hexose Incorrect c. as a disaccharide Correct d. as a polysaccharide Incorrect e. as a monosaccharide Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of Choose one answer. a. Plato. Incorrect b. Hutton. Incorrect c. Lamarck. Correct d. Cuvier. Incorrect e. Darwin. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 An electron loses potential energy when it Choose one answer. a. shifts to a less electronegative atom. Incorrect b. attaches itself to NAD+. Incorrect c. increases its kinetic energy. Incorrect d. shifts to a more electronegative atom. Correct e. increases its activity as an oxidizing agent. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following is used to diagnose hypertension in adults? Choose one answer. a. measurement of the LDL/HDL ratio in peripheral blood Incorrect b. measurement of fatty deposits on the endothelium of arteries Incorrect c. percent of blood volume made up of platelets Incorrect d. number of leukocytes per mm3 of blood Incorrect e. blood pressure of >140 mm Hg systolic and/or >90 diastolic Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? Choose one answer. a. a cell's ability to distinguish one type of neighboring cell from another Correct b. maintaining the integrity of a fluid mosaic membrane Incorrect c. active transport of molecules against their concentration gradients Incorrect d. facilitated diffusion of molecules down their concentration gradients Incorrect e. maintaining membrane fluidity at low temperatures Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following enzymes works most effectively at a very low pH? Choose one answer. a. pancreatic lipase Incorrect b. trypsin Incorrect c. pancreatic amylase Incorrect d. pepsin Correct e. salivary amylase Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of Choose one answer. a. uniformitarianism. Incorrect b. the origin of new species. Incorrect c. evolution. Incorrect d. the fossil record. Correct e. natural selection. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 One of two major forms of a human condition called neurofibromatosis (NF 1) is inherited as a dominant, although it may be either mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation? Choose one answer. a. The mother carries the gene but does not express it at all. Incorrect b. The condition skipped a generation in the family. Incorrect c. The child has a different allele of the gene than the parents. Incorrect d. One of the parents has very mild expression of the gene. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following properties or processes do we associate with living things? Choose one answer. a. all of the above Correct b. responding to the environment Incorrect c. growth and reproduction Incorrect d. energy processing Incorrect e. evolutionary adaptations Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Meiosis II is similar to mitosis in that Choose one answer. a. the daughter cells are diploid. Incorrect b. the chromosome number is reduced. Incorrect c. homologous chromosomes synapse. Incorrect d. sister chromatids separate during anaphase. Correct e. DNA replicates before the division. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. primary cell wall ? plasma membrane ? cytoplasm ? tonoplast Correct b. primary cell wall ? plasma membrane ? tonoplast ? cytoplasm ? vacuole Incorrect c. secondary cell wall ? plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect d. plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect e. tonoplast ? primary cell wall ? plasma membrane ? cytoplasm Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. a. Only heterotrophs require oxygen. Incorrect b. Only heterotrophs require chemical compounds from the environment. Incorrect c. Cellular respiration is unique to heterotrophs. Incorrect d. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct e. Only heterotrophs have mitochondria. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Water's high specific heat is mainly a consequence of the Choose one answer. a. absorption and release of heat when hydrogen bonds break and form. Correct b. inability of water to dissipate heat into dry air. Incorrect c. small size of the water molecules. Incorrect d. fact that water is a poor heat conductor. Incorrect e. high specific heat of oxygen and hydrogen atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following are distinct from the others in their composition? Choose one answer. a. intermediate filaments Incorrect b. plant cell walls Correct c. microfilaments Incorrect d. nuclear lamina Incorrect e. microtubules Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Why is the velocity of blood flow the lowest in capillaries? Choose one answer. a. The total surface area of the capillaries is larger than the total surface area of the arterioles. Correct b. The capillary walls are not thin enough to allow oxygen to exchange with the cells. Incorrect c. The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. Incorrect d. Capillaries are far from the heart, and blood flow slows as distance from the heart increases. Incorrect e. The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. loss of water in the urine Incorrect b. gain of water through food Correct c. loss of water through the gills Incorrect d. gain of salt through the gills Incorrect e. no drinking of water Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Of the following anatomical structures, which is homologous to the wing of a bird? Choose one answer. a. Wing of a butterfly Incorrect b. Hindlimb of a kangaroo Incorrect c. Flipper of a cetacean Correct d. Dorsal fin of a shark Incorrect e. Tail fin of a flying fish Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which free-living cells were the earliest contributors to the formation of Earth's oxidizing atmosphere? Choose one answer. a. cyanobacteria Correct b. chloroplasts Incorrect c. seaweeds Incorrect d. endosymbionts Incorrect e. mitochondria Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found? Choose one answer. a. cooperativity Incorrect b. both activating and inhibitory activity Incorrect c. an enzyme with more than one subunit Correct d. the need for cofactors Incorrect e. feedback inhibition Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction Choose one answer. a. gains electrons and loses energy. Incorrect b. loses electrons and loses energy. Correct c. neither gains nor loses electrons, but gains or loses energy. Incorrect d. loses electrons and gains energy. Incorrect e. gains electrons and gains energy. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following terms best describes when the phenotype of the heterozygote differs from the phenotypes of both homozygotes? Choose one answer. a. Epistasis Incorrect b. Incomplete dominance Correct c. Multiple alleles Incorrect d. Pleiotropy Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 One of the following people set up a closed system to mimic Earth's early atmosphere and discharged electrical sparks through it. A variety of organic compounds common in organisms were formed. Who did this? Choose one answer. a. Hermann Kolbe Incorrect b. Stanley Miller Correct c. August Kekulé Incorrect d. Friedrich Wohler Incorrect e. Jakob Berzelius Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 The main source of energy for producers in an ecosystem is Choose one answer. a. light energy. Correct b. thermal energy. Incorrect c. ATP. Incorrect d. kinetic energy. Incorrect e. chemical energy. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype? Choose one answer. a. 0% Incorrect b. 50% Correct c. 100% Incorrect d. 75% Incorrect e. 25% Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein? Choose one answer. a. +H, -S, -G Incorrect b. +H, +S, +G Incorrect c. -H, +S, +G Incorrect d. +H, -S, +G Correct e. -H, -S, +G Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 3 Started on Saturday, January 17, 2009, 10:04 AM Completed on Saturday, January 17, 2009, 10:04 AM Time taken 8 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which group possess excretory structures known as protonephridia? Choose one answer. a. cnidarians Incorrect b. insects Incorrect c. vertebrates Incorrect d. earthworms Incorrect e. flatworms Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Obesity in humans is most likely to contribute to which of the following? Choose one answer. a. type II diabetes and decreased insulin production Incorrect b. type I diabetes and prostate cancer Incorrect c. type II diabetes and muscle atrophy Incorrect d. type II diabetes and cardiovascular disease Correct e. type I diabetes and breast cancer Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Where and from what compound(s) is urea produced? Choose one answer. a. kidneys from glycerol and fatty acids Incorrect b. bladder from uric acid and H2O Incorrect c. liver from NH3 and CO2 Correct d. liver from glycogen Incorrect e. kidneys from glucose Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates Choose one answer. a. a dihybrid cross. Incorrect b. true-breeding. Incorrect c. the mistakes made by Mendel. Incorrect d. the blending model of genetics. Incorrect e. dominance. Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes Choose one answer. a. reduced. Correct b. redoxed. Incorrect c. oxidized. Incorrect d. hydrogenated. Incorrect e. a reducing agent. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of these provides evidence of the common ancestry of all life? Choose one answer. a. the ubiquitous use of catalysts by living systems Incorrect b. the universality of the genetic code Correct c. the structure of chloroplasts Incorrect d. the structure of the nucleus Incorrect e. the structure of cilia Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. sugar and O2. Incorrect b. CO2 and ATP. Incorrect c. ATP and NADPH. Correct d. H2O and NADPH. Incorrect e. light energy. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of these are involved in the early stages of blood clotting? Choose one answer. a. immunoglobulins Incorrect b. erythropoietin Incorrect c. platelets Correct d. epinephrine Incorrect e. low-density lipoproteins Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following terms best describes when the phenotype of the heterozygote differs from the phenotypes of both homozygotes? Choose one answer. a. Incomplete dominance Correct b. Pleiotropy Incorrect c. Epistasis Incorrect d. Multiple alleles Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 In order for a protein to be an integral membrane protein it would have to be which of the following? Choose one answer. a. amphipathic Correct b. exposed on only one surface of the membrane Incorrect c. hydrophobic Incorrect d. hydrophilic Incorrect e. completely covered with phospholipids Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is an example of polygenic inheritance? Choose one answer. a. Pink flowers in snapdragons Incorrect b. The ABO blood groups in humans Incorrect c. White and purple flower color in peas Incorrect d. Huntington's disease in humans Incorrect e. Skin pigmentation in humans Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 White blood cells engulf bacteria through what process? Choose one answer. a. exocytosis Incorrect b. osmosis Incorrect c. phagocytosis Correct d. pinocytosis Incorrect e. receptor-mediated exocytosis Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA? Choose one answer. a. S Incorrect b. G0 Incorrect c. M Incorrect d. G2 Correct e. G1 Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. an insect foraging for food Incorrect b. a firefly using light flashes to attract a mate Incorrect c. a boy mowing grass Incorrect d. a food molecule made up of energy-rich macromolecules Correct e. water rushing over Niagara Falls Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 In which group of animals would you expect to find a relatively long cecum? Choose one answer. a. heterotrophs Incorrect b. carnivores Incorrect c. omnivores Incorrect d. herbivores Correct e. autotrophs Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following statements best describes the relationship between photosynthesis and respiration? Choose one answer. a. Photosynthesis stores energy in complex organic molecules, while respiration releases it. Correct b. Photosynthesis occurs only in plants and respiration occurs only in animals. Incorrect c. ATP molecules are produced in photosynthesis and used up in respiration. Incorrect d. Respiration is the reversal of the biochemical pathways of photosynthesis. Incorrect e. Respiration is anabolic and photosynthesis is catabolic. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. Choose one answer. a. 4 ? 1 ? 2 ? 3 Incorrect b. 4 ? 2 ? 3 ? 1 Incorrect c. 4 ? 2 ? 1 ? 3 Incorrect d. 2 ? 4 ? 3 ? 1 Incorrect e. 2 ? 4 ? 1 ? 3 Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than binary fission? Choose one answer. a. Cell division would be faster than binary fission. Incorrect b. Binary fission would not allow the organism to have complex cells. Incorrect c. Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. Correct d. Cell division allows for lower rates of error per chromosome replication. Incorrect e. Binary fission would not allow for the formation of new organisms. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect b. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect c. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct d. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect e. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which of the following nitrogenous wastes requires hardly any water for its excretion? Choose one answer. a. amino acid Incorrect b. nitrogen gas Incorrect c. ammonia Incorrect d. uric acid Correct e. urea Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 If, on average, 46% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be Choose one answer. a. 46% Incorrect b. There is not enough information to say. Incorrect c. 23% Incorrect d. 92% Incorrect e. 54% Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe? Choose one answer. a. Chloroplast inheritance Correct b. Sex-linkage Incorrect c. Genomic imprinting Incorrect d. Mitochondrial inheritance Incorrect e. Infectious inheritance Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which kind of metabolic poison would most directly interfere with glycolysis? Choose one answer. a. an agent that closely mimics the structure of glucose but is not metabolized Correct b. an agent that reacts with NADH and oxidizes it to NAD+ Incorrect c. an agent that binds to pyruvate and inactivates it Incorrect d. an agent that reacts with oxygen and depletes its concentration in the cell Incorrect e. an agent that blocks the passage of electrons along the electron transport chain Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. a. they are necessary coenzymes. Incorrect b. they cannot be manufactured by the organism. Correct c. only those animals use the nutrients. Incorrect d. only some foods contain them. Incorrect e. they are subunits of important polymers. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following is an example of hydrolysis? Choose one answer. a. the reaction of two monosaccharides, forming a disaccharide with the release of water Incorrect b. the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water Incorrect c. the reaction of a fat, forming glycerol and fatty acids with the release of water Incorrect d. the synthesis of two amino acids, forming a peptide with the release of water Incorrect e. the reaction of a fat, forming glycerol and fatty acids with the utilization of water Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 When applying the process of science, which of these is tested? Choose one answer. a. an observation Incorrect b. a question Incorrect c. a result Incorrect d. a prediction Correct e. a hypothesis Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 The average birth weight for human babies is about 3 kg. Which of the following terms best describes this? Choose one answer. a. sexual selection Incorrect b. directional selection Incorrect c. artificial selection Incorrect d. disruptive selection Incorrect e. stabilizing selection Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception. Choose one answer. a. vacant ecological niches Incorrect b. an adaptive radiation in a group of organisms (such as plants) that another group uses as food Incorrect c. colonization of an isolated region that contains suitable habitat and few competitor species Incorrect d. evolutionary innovation Incorrect e. genetic drift Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the G for the new reaction? Choose one answer. a. -20 kcal/mol Correct b. +40 kcal/mol Incorrect c. 0 kcal/mol Incorrect d. -40 kcal/mol Incorrect e. +20 kcal/mol Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Why is it important to know what microscopy method was used to prepare the images you wish to study? Choose one answer. a. so that you can make a judgment about the likelihood of artifacts having been introduced in the preparation Correct b. so that you can know whether to view the image in color or not Incorrect c. so that you can decide whether the image is actually of the size described Incorrect d. so that you can judge whether the images you are seeing are of cells or of organelles Incorrect e. so that you can interpret the correct biochemical process that is occurring Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of these individuals is most likely to be successful in an evolutionary sense? Choose one answer. a. a female who mates with 20 males and produces 1 offspring Incorrect b. a male who mates with 20 females and fathers 1 offspring Incorrect c. a reproductively sterile individual who never falls ill Incorrect d. an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce Correct e. an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? Choose one answer. a. NaOH Incorrect b. glucose Incorrect c. ammonia Correct d. salt Incorrect e. bicarbonate Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 How many structural isomers are possible for a substance having the molecular formula C4H10? Choose one answer. a. 11 Incorrect b. 2 Correct c. 4 Incorrect d. 1 Incorrect e. 3 Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge? Choose one answer. a. nucleus, ribosomes, chloroplasts Incorrect b. nucleus, mitochondria, ribosomes Correct c. vacuoles, ribosomes, nucleus Incorrect d. ribosomes, nucleus, mitochondria Incorrect e. chloroplasts, ribosomes, vacuoles Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Protists and bacteria are grouped into different domains because Choose one answer. a. bacteria decompose protists. Incorrect b. bacteria are not made of cells. Incorrect c. protists have a membrane-bounded nucleus, which bacterial cells lack. Correct d. protists are photosynthetic. Incorrect e. protists eat bacteria. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. a bioinformatic system. Incorrect b. feedback inhibition. Incorrect c. positive feedback. Correct d. enzymatic catalysis. Incorrect e. negative feedback. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? Choose one answer. a. The pH within the thylakoid is less than that of the stroma. Correct b. The pH of the stroma is higher than that of the other two measurements. Incorrect c. There is no consistent relationship. Incorrect d. The pH of the thylakoid space is higher than that anywhere else in the cell. Incorrect e. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis? Choose one answer. a. The animal is obese. Incorrect b. The animal has a very long distance between heart and brain. Correct c. The species is characterized by frequent, quick motions. Incorrect d. The animal is small and does not need the blood pumped far. Incorrect e. The species has very wide diameter veins. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 You have a friend who lost 7 kg (about 15 pounds) of fat on a "low carb" diet. How did the fat leave her body? Choose one answer. a. It was broken down to amino acids and eliminated from the body. Incorrect b. It was released as CO2 and H2O. Correct c. It was converted to ATP, which weighs much less than fat. Incorrect d. Chemical energy was converted to heat and then released. Incorrect e. It was converted to urine and eliminated from the body. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 An example of a hydrogen bond is the bond between Choose one answer. a. Mg+and Cl- in MgCl2. Incorrect b. C and H in methane (CH4). Incorrect c. the H of one water molecule and the O of another water molecule. Correct d. the two hydrogen atoms in a molecule of hydrogen gas (H2). Incorrect e. Na+and Cl- in salt. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Where are the proteins of the electron transport chain located? Choose one answer. a. mitochondrial outer membrane Incorrect b. mitochondrial matrix Incorrect c. cytosol Incorrect d. mitochondrial inner membrane Correct e. mitochondrial intermembrane space Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals? Choose one answer. a. The oxygen dissociation curve for hemocyanin is linear. Incorrect b. Hemocyanin carries appreciably more carbon dioxide. Incorrect c. The protein of hemocyanin is not bound to metal. Incorrect d. Hemocyanin includes cyanic acid. Incorrect e. Hemocyanin has protein coupled to copper rather than iron. Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 PKU (phenylketonuria) is a hereditary condition in which infants and young children cannot ingest any more than tiny amounts of the amino acid phenylalanine without serious neurological results. This damage can be prevented by a severe restriction of phenylalanine in the diet. Which of the following is the nutritional concept that forms the basis for this preventive treatment? Choose one answer. a. essential nutrients Correct b. symbiosis Incorrect c. enzymatic hydrolysis Incorrect d. dehydration synthesis Incorrect e. structural anatomy of the brain Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Males are more often affected by sex-linked traits than females because Choose one answer. a. males are hemizygous for the X chromosome. Correct b. X chromosomes in males generally have more mutations than X chromosomes in females. Incorrect c. male hormones such as testosterone often alter the effects of mutations on the X chromosome. Incorrect d. female hormones such as estrogen often compensate for the effects of mutations on the X. Incorrect e. mutations on the Y chromosome often worsen the effects of X-linked mutations. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? Choose one answer. a. 100 mL of household cleanser containing 0.5M ammonia Correct b. 100 mL of freshly-brewed coffee Incorrect c. 100 mL of pure water Incorrect d. 100 mL of freshly-squeezed orange juice Incorrect e. 100 mL of tomato juice Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. kidneys of vertebrates Correct b. Malpighian tubules of insects Incorrect c. protonephridia of rotifers Incorrect d. metanephridia of earthworms Incorrect e. flame-bulb system of flatworms Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 An electron loses potential energy when it Choose one answer. a. increases its activity as an oxidizing agent. Incorrect b. attaches itself to NAD+. Incorrect c. shifts to a more electronegative atom. Correct d. shifts to a less electronegative atom. Incorrect e. increases its kinetic energy. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Why are hydrocarbons insoluble in water? Choose one answer. a. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. Correct b. They exhibit considerable molecular complexity and diversity. Incorrect c. They are hydrophilic. Incorrect d. They are lighter than water. Incorrect e. The majority of their bonds are polar covalent carbon-to-hydrogen linkages. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which of the following is considered an open system? Choose one answer. a. liquid in a corked bottle Incorrect b. a sealed terrarium Incorrect c. an organism Correct d. food cooking in a pressure cooker Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? Choose one answer. a. It is used to generate ADP from nucleotide precursors. Incorrect b. It is transported to specific organs such as the brain. Incorrect c. It is used to store energy as more ATP. Incorrect d. It is used to power yet more cellular work. Incorrect e. It is lost to the environment. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. a capillary Incorrect b. a portal vessel Incorrect c. an artery Correct d. a venule Incorrect e. a vein Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following is a statement of the first law of thermodynamics? Choose one answer. a. Energy cannot be transferred or transformed. Incorrect b. Kinetic energy is stored energy that results from the specific arrangement of matter. Incorrect c. Energy cannot be created or destroyed. Correct d. The entropy of the universe is constant. Incorrect e. The entropy of the universe is decreasing. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following is true of bile salts? Choose one answer. a. They are enzymes. Incorrect b. They emulsify fats in the duodenum. Correct c. They are normally an ingredient of gastric juice. Incorrect d. They are manufactured by the pancreas. Incorrect e. They increase the efficiency of pepsin action. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they Choose one answer. a. fix CO2 into sugars in the bundle-sheath cells. Incorrect b. fix CO2 into pyruvate in the mesophyll cells. Incorrect c. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. Incorrect d. use photosystems I and II at night. Incorrect e. fix CO2 into organic acids during the night. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are relatively rare. Which of the following terms best describes this? Choose one answer. a. disruptive selection Correct b. directional selection Incorrect c. stabilizing selection Incorrect d. sexual selection Incorrect e. artificial selection Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 A human cell containing 22 autosomes and a Y chromosome is Choose one answer. a. a somatic cell of a female. Incorrect b. a sperm. Correct c. a zygote. Incorrect d. an egg. Incorrect e. a somatic cell of a male. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Chiasmata are what we see under a microscope that let us know which of the following is occurring? Choose one answer. a. Separation of homologs Incorrect b. Crossing over Correct c. Meiosis II Incorrect d. Anaphase II Incorrect e. Asexual reproduction Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. act as reducing agents Incorrect b. both oxidize and reduce during electron transport Correct c. donate electrons Incorrect d. act as oxidizing agents Incorrect e. transport protons within the mitochondria and chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The somatic cells derived from a single-celled zygote divide by which process? Choose one answer. a. replication Incorrect b. mitosis Correct c. binary fission Incorrect d. cytokinesis alone Incorrect e. meiosis Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 What is the voltage across a membrane called? Choose one answer. a. chemical gradient Incorrect b. electrochemical gradient Incorrect c. membrane potential Correct d. water potential Incorrect e. osmotic potential Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 4 Started on Saturday, January 17, 2009, 10:22 AM Completed on Saturday, January 17, 2009, 10:22 AM Time taken 10 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. starch. Incorrect b. sugar. Incorrect c. protein. Incorrect d. fat. Correct e. water. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to Choose one answer. a. myosin denaturation and inhibition of cleavage furrow formation. Incorrect b. inhibition of regulatory protein phosphorylation. Incorrect c. inhibition of DNA synthesis. Incorrect d. disruption of mitotic spindle formation. Correct e. suppression of cyclin production. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype? Choose one answer. a. Normal female Correct b. Enlarged genital structures Incorrect c. Sterile female Incorrect d. Excessive emotional instability Incorrect e. Masculine characteristics such as facial hair Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. water. Incorrect b. pyruvate. Incorrect c. oxygen. Correct d. ADP. Incorrect e. NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 How is most of the carbon dioxide transported by the blood in humans? Choose one answer. a. bicarbonate ions in the plasma Correct b. CO2 dissolved in the plasma Incorrect c. carbonic acid in the erythrocytes Incorrect d. bicarbonate attached to hemoglobin Incorrect e. CO2 attached to hemoglobin Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. is not used by the animal in biosynthesis. Incorrect b. is not found in many proteins. Incorrect c. is less important than an essential amino acid. Incorrect d. must be ingested in the diet. Incorrect e. can be made by the animal's body from other substances. Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct b. Every cell uses DNA as its genetic information. Incorrect c. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect d. Every cell is enclosed by a membrane. Incorrect e. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? Choose one answer. a. active transport pumps Incorrect b. simple diffusion Incorrect c. phagocytosis Incorrect d. facilitated diffusion Correct e. exocytosis Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 What would be the long-term effect if the lymphatic vessels associated with a capillary bed were to become blocked? Choose one answer. a. Fluid would accumulate in interstitial areas. Correct b. Fewer proteins would leak into the interstitial fluid from the blood. Incorrect c. More fluid would enter the venous capillaries. Incorrect d. Blood pressure in the capillary bed would increase. Incorrect e. Nothing would happen. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which cell would be best for studying lysosomes? Choose one answer. a. muscle cell Incorrect b. bacterial cell Incorrect c. leaf cell of a plant Incorrect d. phagocytic white blood cell Correct e. nerve cell Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ? Choose one answer. a. The appendix can be surgically removed with no immediate ill effects. Incorrect b. The appendix might have been larger in fossil hominids. Incorrect c. The appendix has a substantial amount of defensive lymphatic tissue. Correct d. Individuals with a larger-than-average appendix leave fewer offspring than those with a below-average-sized appendix. Incorrect e. In a million years, the human species might completely lack an appendix. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Tidal volume in respiration is analogous to what measurement in cardiac physiology? Choose one answer. a. heart rate Incorrect b. stroke volume Correct c. diastolic pressure Incorrect d. systolic pressure Incorrect e. cardiac output Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, Choose one answer. a. chloroplasts and peroxisomes. Incorrect b. chloroplasts and mitochondria. Correct c. peroxisomes and chloroplasts. Incorrect d. mitochondria and chloroplasts. Incorrect e. mitochondria and peroxisomes. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt × BBtt will have black fur and long tails? Choose one answer. a. 9/16 Incorrect b. 1/2 Correct c. 3/8 Incorrect d. 1/16 Incorrect e. 3/16 Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing Choose one answer. a. genetic drift. Incorrect b. non-random mating. Incorrect c. gene flow. Correct d. geographic isolation. Incorrect e. mutations. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a Choose one answer. a. C4 plant. Correct b. CAM plant. Incorrect c. C3 plant. Incorrect d. chemoautotroph. Incorrect e. heterotroph. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following is true of the evolution of cell membranes? Choose one answer. a. An individual organism selects its preferred type of cell membrane for particular functions. Incorrect b. Cell membranes cannot evolve if proteins do not. Incorrect c. As populations of organisms evolve, different properties of their cell membranes are selected for or against. Correct d. Cell membranes have stopped evolving now that they are fluid mosaics. Incorrect e. The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. a. The concentration of OH- ions in the water is 7 times the concentration of H+ ions in the water. Incorrect b. there are no H+ ions in the water. Incorrect c. the concentration of H+ ions in the water is 7 times the concentration of OH- ions in the water. Incorrect d. there are no OH- ions in the water. Incorrect e. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following enzymes has the lowest pH optimum? Choose one answer. a. pepsin Correct b. lipase Incorrect c. sucrase Incorrect d. amylase Incorrect e. trypsin Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? Choose one answer. a. denaturization of the enzyme Incorrect b. allosteric inhibition Incorrect c. competitive inhibition Correct d. insufficient cofactors Incorrect e. saturation of the enzyme activity Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. Bowman's capsule Incorrect b. loop of Henle Incorrect c. proximal tubule Incorrect d. distal tubules Correct e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? Choose one answer. a. It must be an animal. Incorrect b. Its gametes must have 23 chromosomes. Correct c. It must be human. Incorrect d. It must be a primate. Incorrect e. It must be sexually reproducing. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. uric acid Correct b. urea Incorrect c. nitrate Incorrect d. nitrite Incorrect e. ammonia Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Why did the improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics? Choose one answer. a. It revealed new and unanticipated features of Mendel's pea plant varieties. Incorrect b. It allowed scientists to see the DNA present within chromosomes. Incorrect c. It led to the discovery of mitochondria. Incorrect d. It allowed the study of meiosis and mitosis, revealing parallels between behaviors of genes and chromosomes. Correct e. It showed genes functioning to direct the formation of enzymes. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 A newspaper ad for a local toy store indicates that a very inexpensive microscope available for a small child is able to magnify specimens nearly as much as the much more costly microscope available in your college lab. What is the primary reason for the price difference? Choose one answer. a. The toy microscope usually uses a different wavelength of light source. Incorrect b. The ad agency is misrepresenting the ability of the toy microscope to magnify. Incorrect c. The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images. Correct d. The toy microscope does not have the same fine control for focus of the specimen. Incorrect e. The college microscope produces greater contrast in the specimens. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 A chemical reaction that has a positive G is correctly described as Choose one answer. a. enthalpic. Incorrect b. endergonic. Correct c. exothermic. Incorrect d. spontaneous. Incorrect e. endothermic. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be Choose one answer. a. 0.25x. Incorrect b. x. Incorrect c. 2x. Correct d. 0.5x. Incorrect e. 4x. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Water's high specific heat is mainly a consequence of the Choose one answer. a. small size of the water molecules. Incorrect b. inability of water to dissipate heat into dry air. Incorrect c. fact that water is a poor heat conductor. Incorrect d. absorption and release of heat when hydrogen bonds break and form. Correct e. high specific heat of oxygen and hydrogen atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 A gene is considered to be non-Mendelian in its inheritance pattern if it seems to "violate" Mendel's laws. Which of the following would then NOT be considered non-Mendelian? Choose one answer. a. A gene whose expression varies depending on the gender of the transmitting parent Incorrect b. A gene transmitted via the cytoplasm or cytoplasmic structures Incorrect c. A gene derived solely from maternal inheritance Incorrect d. A gene transmitted by a virus to egg-producing cells Incorrect e. A gene transmitted to males from the maternal line and from fathers to daughters Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect b. There is no relationship between the light reactions and the Calvin cycle. Incorrect c. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect d. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct e. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which kind of metabolic poison would most directly interfere with glycolysis? Choose one answer. a. an agent that binds to pyruvate and inactivates it Incorrect b. an agent that blocks the passage of electrons along the electron transport chain Incorrect c. an agent that reacts with oxygen and depletes its concentration in the cell Incorrect d. an agent that closely mimics the structure of glucose but is not metabolized Correct e. an agent that reacts with NADH and oxidizes it to NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is a nutritional monomer that can be transported in the blood? Choose one answer. a. maltose Incorrect b. fatty acid Correct c. sucrose Incorrect d. dipeptide Incorrect e. trinucleotide Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? Choose one answer. a. Relationships between DNA sequences among the species did not match relationships between skeletal patterns. Correct b. None of the organisms depicted by the tree ate the same foods. Incorrect c. Some of the organisms depicted by the tree had lived in different habitats. Incorrect d. The skeletal remains of the organisms depicted by the tree were incomplete (i.e., some bones were missing). Incorrect e. Transitional fossils had not been found. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses Choose one answer. a. 4, 1, 3, 2, 5 Correct b. 3, 4, 1, 2, 5 Incorrect c. 4, 3, 2, 1, 5 Incorrect d. 4, 3, 1, 5, 2 Incorrect e. 4, 1, 2, 3, 5 Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. loop of Henle Correct b. Bowman's capsule Incorrect c. glomerulus Incorrect d. collecting duct Incorrect e. proximal convoluted tubule Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which of the following would be described as a portal system? Choose one answer. a. an area connecting arterioles to venules Incorrect b. a series of vessels that returns blood to the heart in an animal with an open circulatory system Incorrect c. a vessel or vessels connecting two capillary beds Correct d. a space within or between organs where blood is allowed to pool Incorrect e. a slightly muscular vessel that has minimal pumping action in an organism with no heart Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. a. People living in equatorial areas of the world Incorrect b. No groups have such higher frequency Correct c. People in Latin or South America Incorrect d. The Inuit and other peoples in very cold habitats Incorrect e. Very small population groups Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which definition of evolution would have been most foreign to Charles Darwin during his lifetime? Choose one answer. a. the gradual change of a population's heritable traits over generations Incorrect b. descent with modification Incorrect c. change in gene frequency in gene pools Correct d. populations becoming better adapted to their environments over the course of generations Incorrect e. the appearance of new varieties and new species with the passage of time Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. a. 38 ATP, 6 CO2, 3 NADH, and 12 FADH2 Incorrect b. 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 Incorrect c. 2 ATP, 2 CO2, 1 NADH, and 3 FADH2 Incorrect d. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct e. 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Processing of filtrate in the proximal and distal tubules accomplishes what important function? Choose one answer. a. maintaining a constant pH in body fluids Correct b. reabsorbing urea to maintain osmotic balance Incorrect c. sorting plasma proteins according to size Incorrect d. regulating the speed of blood flow through the nephron Incorrect e. converting toxic ammonia to less toxic urea Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of Choose one answer. a. 120 cytosine and 120 thymine molecules. Incorrect b. 120 adenine and 120 uracil molecules. Incorrect c. 120 thymine and 120 adenine molecules. Correct d. 240 adenine and 240 cytosine molecules. Incorrect e. 240 guanine and 240 thymine molecules. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. NAD+ Incorrect b. lactate Incorrect c. NADH Correct d. pyruvate Incorrect e. oxygen Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 A gene's location along a chromosome is known as which of the following? Choose one answer. a. Trait Incorrect b. Variant Incorrect c. Sequence Incorrect d. Locus Correct e. Allele Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Meiosis II is similar to mitosis in that Choose one answer. a. DNA replicates before the division. Incorrect b. homologous chromosomes synapse. Incorrect c. the chromosome number is reduced. Incorrect d. the daughter cells are diploid. Incorrect e. sister chromatids separate during anaphase. Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. sugar and O2. Incorrect b. CO2 and ATP. Incorrect c. H2O and NADPH. Incorrect d. light energy. Incorrect e. ATP and NADPH. Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) is exactly or very approximately equal to item (B). Correct b. Item (A) is greater than item (B). Incorrect c. Item (A) is less than item (B). Incorrect d. Item (A) may stand in more than one of the above relations to item (B). Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Photorespiration lowers the efficiency of photosynthesis by preventing the formation of Choose one answer. a. carbon dioxide molecules. Incorrect b. 3-phosphoglycerate molecules Correct c. RuBP carboxylase molecules. Incorrect d. ATP molecules. Incorrect e. ribulose bisphosphate molecules. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? Choose one answer. a. by changing the shape of a reactant Correct b. by decreasing the activation energy of the reaction Incorrect c. by binding at the active site of the enzyme Incorrect d. by changing the free energy change of the reaction Incorrect e. by acting as a coenzyme for the reaction Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which branch of biology is concerned with the naming and classifying of organisms? Choose one answer. a. informatics Incorrect b. schematic biology Incorrect c. genomics Incorrect d. evolution Incorrect e. taxonomy Correct Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Most cells cannot harness heat to perform work because Choose one answer. a. cells do not have much heat; they are relatively cool. Incorrect b. heat can never be used to do work. Incorrect c. heat denatures enzymes. Incorrect d. temperature is usually uniform throughout a cell. Correct e. heat is not a form of energy. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A controlled experiment is one that Choose one answer. a. proceeds slowly enough that a scientist can make careful records of the results. Incorrect b. keeps all environmental variables constant. Incorrect c. is supervised by an experienced scientist. Incorrect d. is repeated many times to make sure the results are accurate. Incorrect e. may include experimental groups and control groups tested in parallel. Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Obesity in humans is most likely to contribute to which of the following? Choose one answer. a. type II diabetes and cardiovascular disease Correct b. type I diabetes and breast cancer Incorrect c. type II diabetes and decreased insulin production Incorrect d. type I diabetes and prostate cancer Incorrect e. type II diabetes and muscle atrophy Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________. Choose one answer. a. plants; animals Incorrect b. producers; consumers Incorrect c. sunlight; heat Correct d. plants; heat Incorrect e. heat; light Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. bringing glucose and fructose together to form sucrose. Incorrect b. utilization of water as a covalent bond is formed between glucose and fructose to form sucrase. Incorrect c. production of water from the sugar as bonds are broken between the glucose monomers. Incorrect d. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct e. the release of water from sucrose as the bond between glucose and fructose is broken. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 What is the structural feature that allows DNA to replicate? Choose one answer. a. complementary pairing of the nitrogenous bases Correct b. three-component structure of the nucleotides Incorrect c. sugar-phosphate backbone Incorrect d. twisting of the molecule to form an a helix Incorrect e. disulfide bonding (bridging) of the two helixes Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Organisms categorized as osmoconformers are most likely Choose one answer. a. found in fresh water lakes and streams. Incorrect b. amphibious. Incorrect c. marine. Correct d. found in arid terrestrial environments. Incorrect e. found in terrestrial environments with adequate moisture. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following respiratory systems is not closely associated with a blood supply? Choose one answer. a. the skin of an earthworm Incorrect b. the lungs of a vertebrate Incorrect c. the parapodia of a polychaete worm Incorrect d. the tracheal system of an insect Correct e. the gills of a fish Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 In terms of the hierarchical organization of life, a bacterium is at the __________ level of organization, whereas a human is at the __________ level of organization. Choose one answer. a. tissue; organism Incorrect b. single-celled organism; multicellular organism Correct c. single tissue; multicellular organism Incorrect d. single organelle; organism Incorrect e. organelle; organ system Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 In mitochondria, exergonic redox reactions Choose one answer. a. are directly coupled to substrate-level phosphorylation. Incorrect b. are the source of energy driving prokaryotic ATP synthesis. Incorrect c. provide the energy that establishes the proton gradient. Correct d. are coupled via phosphorylated intermediates to endergonic processes. Incorrect e. reduce carbon atoms to carbon dioxide. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 In thylakoids, protons travel through ATP synthase from the stroma to the thylakoid space. Therefore the catalytic "knobs" of ATP synthase would be located Choose one answer. a. on the pigment molecules of PSI and PSII. Incorrect b. built into the center of the thylkoid stack (granum). Incorrect c. on the ATP molecules themselves. Incorrect d. on the side facing the thylakoid space. Incorrect e. on the stroma side of the membrane. Correct Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 5 Started on Saturday, January 17, 2009, 10:26 AM Completed on Saturday, January 17, 2009, 10:26 AM Time taken 9 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. a. Better adapted members of a species will survive and reproduce more successfully. Incorrect b. Every organism has the potential to produce more offspring than the local environment can support. Incorrect c. Most individuals in a species do not survive to reproduce. Incorrect d. Characteristics of organisms are inherited as genes on chromosomes. Correct e. Slight inheritable variations within a population may make an individual significantly more or less likely to survive in its environment, and thus to reproduce. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. a. the starch solution has less free energy than the sugar solution. Incorrect b. the hydrolysis of starch to sugar is endergonic. Incorrect c. the activation energy barrier for this reaction cannot be surmounted. Correct d. starch cannot be hydrolyzed in the presence of so much water. Incorrect e. starch hydrolysis is nonspontaneous. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 In hypothesis-based science, deductive reasoning is used to predict a result that would be found if a particular hypothesis is correct. Answer: True False Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 In which blood vessel is glucose concentration likely to vary the most? Choose one answer. a. hepatic portal vessel Correct b. hepatic vein, which drains the liver Incorrect c. pulmonary veins Incorrect d. coronary arteries Incorrect e. abdominal artery Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following statements is true of mammals? Choose one answer. a. Enzyme production continues in the esophagus. Incorrect b. After leaving the oral cavity, the bolus enters the larynx. Incorrect c. The epiglottis prevents food from entering the trachea. Correct d. The trachea leads to the esophagus and then to the stomach. Incorrect e. All foods begin their enzymatic digestion in the mouth. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which is the longest of the mitotic stages? Choose one answer. a. anaphase Incorrect b. prophase Incorrect c. telophase Incorrect d. metaphase Correct e. prometaphase Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 What causes the decrease in the amount of cyclin at a specific point in the cell cycle? Choose one answer. a. the binding of PDGF to receptors on the cell surface Incorrect b. the cascade of increased production once its protein is phosphorylated by Cdk Incorrect c. the changing ratio of cytoplasm to genome Incorrect d. its destruction by a process initiated by the activity of its complex with a cyclin Correct e. an increase in production once the restriction point is passed Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Organisms categorized as osmoconformers are most likely Choose one answer. a. amphibious. Incorrect b. found in terrestrial environments with adequate moisture. Incorrect c. found in arid terrestrial environments. Incorrect d. found in fresh water lakes and streams. Incorrect e. marine. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as Choose one answer. a. reversible inhibition. Incorrect b. metabolic inhibition. Incorrect c. feedback inhibition. Correct d. noncooperative inhibition. Incorrect e. allosteric inhibition. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 A nonfunctional sinoatrial node would Choose one answer. a. cause no effects because hormones will take over regulation of the heartbeat. Incorrect b. have little significant effect on stroke volume. Correct c. have no adverse effects on heart contraction. Incorrect d. result in a block in ventricular contractions. Incorrect e. cause the heart to stop beating in an autorhythmic fashion. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. oxidize NADH to NAD+. Correct b. reduce NAD+ to NADH. Incorrect c. none of the above Incorrect d. reduce FADH2 to FAD+. Incorrect e. reduce FAD+ to FADH2. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 One of the following people set up a closed system to mimic Earth's early atmosphere and discharged electrical sparks through it. A variety of organic compounds common in organisms were formed. Who did this? Choose one answer. a. Jakob Berzelius Incorrect b. August Kekulé Incorrect c. Stanley Miller Correct d. Hermann Kolbe Incorrect e. Friedrich Wohler Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Numerous adult humans are currently treated for reflux disorders. However, at an earlier time in medical history these same individuals probably would have been diagnosed with gastric ulcers. Which of the following has most contributed to correct diagnosis of this problem? Choose one answer. a. ability to perform colonoscopy Incorrect b. ability to perform sonography Incorrect c. better pH monitoring Incorrect d. improvements in X-ray technology Incorrect e. ability to diagnose and treat H. pylori infection Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? Choose one answer. a. They are free to depart from the membrane and dissolve in the surrounding solution. Incorrect b. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. Incorrect c. They can move laterally along the plane of the membrane. Correct d. They have hydrophilic tails in the interior of the membrane. Incorrect e. They frequently flip-flop from one side of the membrane to the other. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect b. direct exchange of nutrients with the surrounding medium Incorrect c. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect d. a system to circulate gases, nutrients, and wastes to and from cells Correct e. a system of individualized exchange tubules for each cell group Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 An important group of peripheral membrane proteins are enzymes, such as the phospholipases that attack the head groups of phospholipids leading to the degradation of damaged membranes. What properties must these enzymes exhibit? Choose one answer. a. independence from cofactor interaction Incorrect b. water solubility Correct c. membrane spanning domains Incorrect d. resistance to degradation Incorrect e. lipid solubility Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Pulse is a direct measure of Choose one answer. a. heart rate. Correct b. stroke volume. Incorrect c. breathing rate. Incorrect d. cardiac output. Incorrect e. blood pressure. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Recent evidence shows that the extracellular matrix can take part in regulating the expression of genes. A likely possibility for this might be which of the following? Choose one answer. a. Orientation of microfilaments to the ECM can change the gene activity. Incorrect b. Fibronectin binds to integrins built into the plasma membrane. Incorrect c. Intracellular signals might cause changes in the fibronectin binding to the cell surface. Incorrect d. Proteoglycans in the ECM become large enough in aggregate to force genetic alteration. Incorrect e. Mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signaling. Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which functional groups can act as acids? Choose one answer. a. ketone and amino Incorrect b. carboxyl and phosphate Correct c. hydroxyl and aldehyde Incorrect d. amine and sulfhydryl Incorrect e. carbonyl and carboxyl Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve? Choose one answer. a. It allows for increased rate of glycolysis. Incorrect b. It allows for increased rate of the citric acid cycle. Incorrect c. It increases the surface for substrate-level phosphorylation. Incorrect d. It allows the liver cell to have fewer mitochondria. Incorrect e. It increases the surface for oxidative phosphoryation. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. sugar. Incorrect b. fat. Correct c. water. Incorrect d. protein. Incorrect e. starch. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Compared to the seawater around them, most marine invertebrates are Choose one answer. a. isoosmotic. Correct b. hyperosmotic. Incorrect c. hypoosmotic and isoosmotic. Incorrect d. hyperosmotic and isoosmotic. Incorrect e. hypoosmotic. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the Choose one answer. a. creation of a proton gradient. Correct b. lowering of pH in the mitochondrial matrix. Incorrect c. formation of ATP. Incorrect d. reduction of NAD+. Incorrect e. restoration of the Na+/K+ balance across the membrane. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. P700 and P680 Incorrect b. ATP and NADPH Correct c. heat and fluorescence Incorrect d. ATP and P700 Incorrect e. ADP and NADP Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following is not an observation or inference on which natural selection is based? Choose one answer. a. Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less suited. Incorrect b. Poorly adapted individuals never produce offspring. Correct c. Only a fraction of the offspring produced by an individual may survive. Incorrect d. There is heritable variation among individuals. Incorrect e. Species produce more offspring than the environment can support. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Plantae Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Fungi Correct e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following? Choose one answer. a. His reading and discussion of Darwin's Origin of Species Incorrect b. His reading of the scientific literature current in the field Incorrect c. The understanding of particulate inheritance he learned from renowned scientists of his time Incorrect d. His discussions of heredity with his colleagues at major universities Incorrect e. His experiments with the breeding of plants such as peas Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? Choose one answer. a. animal Incorrect b. fungi Incorrect c. protists Incorrect d. archaea Correct e. plant Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect b. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct c. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect d. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect e. protein function at one site affected by binding at another of its active sites Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the following statements correctly describes geometric isomers? Choose one answer. a. Their atoms and bonds are arranged in different sequences. Incorrect b. They have different molecular formulas. Incorrect c. They have variations in arrangement around a double bond. Correct d. They have the same chemical properties. Incorrect e. They have an asymmetric carbon that makes them mirror images. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 According to the concept of punctuated equilibrium, Choose one answer. a. given enough time, most existing species will branch gradually into new species. Incorrect b. a new species accumulates most of its unique features as it comes into existence. Correct c. natural selection is unimportant as a mechanism of evolution. Incorrect d. evolution of new species features long periods during which changes are occurring, interspersed with short periods of equilibrium, or stasis. Incorrect e. transitional fossils, intermediate between newer species and their parent species, should be abundant. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. a. Only heterotrophs have mitochondria. Incorrect b. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct c. Cellular respiration is unique to heterotrophs. Incorrect d. Only heterotrophs require oxygen. Incorrect e. Only heterotrophs require chemical compounds from the environment. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 A freshwater fish was accidentally placed in salt water. After several minutes in this saline water, it died. What is the most logical explanation for its death? Choose one answer. a. The kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment creating an irrevocable loss of homeostasis. Incorrect b. The gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation. Incorrect c. Loss of water by osmosis in cells in vital organs resulting in cell death and eventually organ failure. Correct d. Brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment; death by loss of autonomic function. Incorrect e. Salt diffused into all the fish's cells causing them to swell and, in some cases, lyse. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by Choose one answer. a. nonpolar covalent bonds. Incorrect b. hydrogen bonds. Incorrect c. van der Waals interactions. Incorrect d. ionic bonds. Incorrect e. polar covalent bonds. Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The diaphragm contracts. Incorrect b. The residual volume of the lungs decreases. Incorrect c. The rib cage expands. Incorrect d. The epiglottis closes. Incorrect e. The volume of the thoracic cavity decreases. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. a. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct b. 38 ATP, 6 CO2, 3 NADH, and 12 FADH2 Incorrect c. 2 ATP, 2 CO2, 1 NADH, and 3 FADH2 Incorrect d. 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 Incorrect e. 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which group is composed entirely of individuals who maintained that species are fixed (i.e., unchanging)? Choose one answer. a. Aristotle, Linnaeus, and Cuvier Correct b. Linnaeus, Cuvier, and Lamarck Incorrect c. Lyell, Linnaeus, and Lamarck Incorrect d. Aristotle, Cuvier, and Lamarck Incorrect e. Hutton, Lyell, and Darwin Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following processes includes all others? Choose one answer. a. transport of an ion down its electrochemical gradient Incorrect b. passive transport Correct c. diffusion of a solute across a membrane Incorrect d. osmosis Incorrect e. facilitated diffusion Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is oxidized. Incorrect b. The excess is stored as glycogen. Correct c. The excess is eliminated. Incorrect d. The excess is hydrolyzed. Incorrect e. The excess is stored as starch. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following does not occur during the Calvin cycle? Choose one answer. a. regeneration of the CO2 acceptor Incorrect b. oxidation of NADPH Incorrect c. release of oxygen Correct d. carbon fixation Incorrect e. consumption of ATP Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 The blood level of which gas is most important in controlling human respiration rate? Choose one answer. a. nitric acid Incorrect b. nitrogen Incorrect c. oxygen Incorrect d. carbon dioxide Correct e. carbon monoxide Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 DNA is replicated at this time of the cell cycle: Choose one answer. a. G0 Incorrect b. G2 Incorrect c. G1 Incorrect d. S Correct e. M Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend? Choose one answer. a. the enzyme becoming too saturated because of the concentration of substrate Incorrect b. the ability of an enzyme to form a template for holding and joining molecules Correct c. the enzyme forming covalent bonds with the reactants Incorrect d. the enzyme providing an appropriate microenvironment conducive to a reaction's occurrence Incorrect e. the enzyme's ability to stretch reactants and move them toward a transition state Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Skin color in a certain species of fish is inherited via a single gene with four different alleles. How many different types of gametes would be possible in this system? Choose one answer. a. 2 Incorrect b. 16 Incorrect c. 1 Incorrect d. 8 Incorrect e. 4 Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 A nonreciprocal crossover causes which of the following products? Choose one answer. a. Deletion and duplication Correct b. Deletion only Incorrect c. Duplication and nondisjunction Incorrect d. Duplication only Incorrect e. Nondisjunction Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Why do chromosomes coil during mitosis? Choose one answer. a. to allow the chromosomes to move without becoming entangled and breaking Correct b. to provide for the structure of the centromere Incorrect c. to allow the chromosomes to fit within the nuclear envelope Incorrect d. to allow the sister chromatids to remain attached Incorrect e. to increase their potential energy Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect b. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct c. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect d. It may explain the transmission of Duchenne muscular dystrophy. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Male satin bowerbirds adorn structures that they build, called "bowers," with parrot feathers, flowers, and other bizarre ornaments in order to attract females. Females inspect the bowers and, if suitably impressed, allow males to mate with them. The evolution of this male behavior is due to Choose one answer. a. disruptive selection. Incorrect b. frequency-dependent selection. Incorrect c. artificial selection. Incorrect d. natural selection. Incorrect e. sexual selection. Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 The reaction-center chlorophyll of photosystem I is known as P700 because Choose one answer. a. this pigment is best at absorbing light with a wavelength of 700 nm. Correct b. there are 700 chlorophyll molecules in the center. Incorrect c. there are 700 photosystem I components to each chloroplast. Incorrect d. the plastoquinone reflects light with a wavelength of 700 nm. Incorrect e. it absorbs 700 photons per microsecond. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Of the following, which cell structure would most likely be visible with a light microscope that has been manufactured to the maximum resolving power possible? Choose one answer. a. largest microfilament Incorrect b. mitochondrion Correct c. ribosome Incorrect d. microtubule Incorrect e. nuclear pore Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) is greater than item (B). Incorrect b. Item (A) is exactly or very approximately equal to item (B). Correct c. Item (A) may stand in more than one of the above relations to item (B). Incorrect d. Item (A) is less than item (B). Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 In the cells of some organisms, mitosis occurs without cytokinesis. This will result in Choose one answer. a. cell cycles lacking an S phase. Incorrect b. destruction of chromosomes. Incorrect c. cells with more than one nucleus. Correct d. cells that are unusually small. Incorrect e. cells lacking nuclei. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? Choose one answer. a. the Golgi apparatus Incorrect b. the endoplasmic reticulum Incorrect c. membrane-bound ribosomes Incorrect d. mitochondria Incorrect e. the lysosome Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In modern terminology, diversity is understood to be a result of genetic variation. Sources of variation for evolution include all of the following except Choose one answer. a. recombination by crossing over in meiosis. Incorrect b. mistakes in translation of structural genes. Correct c. recombination at fertilization. Incorrect d. mistakes in DNA replication. Incorrect e. translocations and mistakes in meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 What would account for increased urine production as a result of drinking alcoholic beverages? Choose one answer. a. increased reabsorption of water in the proximal tubule Incorrect b. inhibition of antidiuretic hormone secretion (ADH) Correct c. the osmoregulator cells of the brain increasing their activity Incorrect d. increased aldosterone production Incorrect e. increased blood pressure Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. a. Hypotheses and theories are essentially the same thing. Incorrect b. Hypotheses are guesses; theories are correct answers. Incorrect c. Theories are hypotheses that have been proved. Incorrect d. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct e. Theories are proved true in all cases; hypotheses are usually falsified by tests. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. donate electrons Incorrect b. both oxidize and reduce during electron transport Correct c. transport protons within the mitochondria and chloroplasts Incorrect d. act as reducing agents Incorrect e. act as oxidizing agents Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype? Choose one answer. a. 100% Incorrect b. 0% Incorrect c. 25% Incorrect d. 50% Correct e. 75% Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? Choose one answer. a. glucose Incorrect b. bicarbonate Incorrect c. salt Incorrect d. NaOH Incorrect e. ammonia Correct Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. ADP + Pi Incorrect b. NADH Incorrect c. NAD+ Incorrect d. ATP Incorrect e. FADH2 Correct Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 6 Started on Saturday, January 17, 2009, 10:27 AM Completed on Saturday, January 17, 2009, 10:27 AM Time taken 14 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 All of the following are polysaccharides except Choose one answer. a. cellulose Incorrect b. chitin Incorrect c. starch Incorrect d. amylopectin Incorrect e. glycogen Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than binary fission? Choose one answer. a. Cell division would be faster than binary fission. Incorrect b. Cell division allows for lower rates of error per chromosome replication. Incorrect c. Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. Correct d. Binary fission would not allow the organism to have complex cells. Incorrect e. Binary fission would not allow for the formation of new organisms. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 An organism with a cell wall would have the most difficulty doing which process? Choose one answer. a. active transport Incorrect b. osmosis Incorrect c. diffusion Incorrect d. facilitated diffusion Incorrect e. phagocytosis Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? Choose one answer. a. gametic isolation Incorrect b. reduced hybrid fertility Incorrect c. mechanical isolation Incorrect d. habitat isolation Correct e. hybrid breakdown Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 What was the prevailing notion prior to the time of Lyell and Darwin? Choose one answer. a. Earth is a few thousand years old, and populations are unchanging. Correct b. Earth is millions of years old, and populations rapidly change. Incorrect c. Earth is millions of years old, and populations are unchanging. Incorrect d. Earth is a few thousand years old, and populations gradually change. Incorrect e. Earth is millions of years old, and populations gradually change. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 At an atmospheric pressure of 870 mm Hg, what is the contribution of oxygen? Choose one answer. a. 219 mm Hg Incorrect b. 151 mm Hg Incorrect c. 182 mm Hg Correct d. 127 mm Hg Incorrect e. 100 mm Hg Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found? Choose one answer. a. the need for cofactors Incorrect b. an enzyme with more than one subunit Correct c. both activating and inhibitory activity Incorrect d. feedback inhibition Incorrect e. cooperativity Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause? Choose one answer. a. The woman inherited this tendency from her parents. Incorrect b. One member of the couple underwent nondisjunction in gamete production. Correct c. One member of the couple carried a translocation. Incorrect d. One member of the couple underwent nondisjunction in somatic cell production. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 When oxygen is released as a result of photosynthesis, it is a by-product of which of the following? Choose one answer. a. the electron transfer system of photosystem I Incorrect b. reducing NADP+ Incorrect c. the electron transfer system of photosystem II Incorrect d. chemiosmosis Incorrect e. splitting the water molecules Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 What is the chromosomal system for determining sex in mammals? Choose one answer. a. X-X Incorrect b. Haploid-diploid Incorrect c. X-0 Incorrect d. Z-W Incorrect e. X-Y Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________. Choose one answer. a. sunlight; heat Correct b. producers; consumers Incorrect c. plants; animals Incorrect d. heat; light Incorrect e. plants; heat Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of these provides evidence of the common ancestry of all life? Choose one answer. a. the ubiquitous use of catalysts by living systems Incorrect b. the universality of the genetic code Correct c. the structure of the nucleus Incorrect d. the structure of cilia Incorrect e. the structure of chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. pyruvate Incorrect b. lactate Incorrect c. NAD+ Incorrect d. oxygen Incorrect e. NADH Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 The body fluids of an osmoconformer would be __________ with its __________ environment. Choose one answer. a. isotonic; freshwater Incorrect b. hypoosmotic; saltwater Incorrect c. hyperosmotic; saltwater Incorrect d. hyperosmotic; freshwater Incorrect e. isoosmotic; saltwater Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they Choose one answer. a. fix CO2 into organic acids during the night. Correct b. fix CO2 into pyruvate in the mesophyll cells. Incorrect c. fix CO2 into sugars in the bundle-sheath cells. Incorrect d. use photosystems I and II at night. Incorrect e. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following is considered an open system? Choose one answer. a. food cooking in a pressure cooker Incorrect b. liquid in a corked bottle Incorrect c. an organism Correct d. a sealed terrarium Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 The decline of MPF activity at the end of mitosis is due to Choose one answer. a. synthesis of DNA. Incorrect b. the degradation of cyclin. Correct c. decreased synthesis of cyclin. Incorrect d. an increase in the cell's volume-to-genome ratio. Incorrect e. the destruction of the protein kinase Cdk. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis? Choose one answer. a. The animal is small and does not need the blood pumped far. Incorrect b. The species is characterized by frequent, quick motions. Incorrect c. The species has very wide diameter veins. Incorrect d. The animal has a very long distance between heart and brain. Correct e. The animal is obese. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? Choose one answer. a. inability of the nucleus to keep out destructive chemicals Incorrect b. failure of chromosomes to carry genetic information Incorrect c. the loss of all nuclear function Incorrect d. the inability of the cell to withstand enzymatic digestion Incorrect e. a change in the shape of the nucleus Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. gain of water through food Correct b. loss of water in the urine Incorrect c. no drinking of water Incorrect d. gain of salt through the gills Incorrect e. loss of water through the gills Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. a. tubeworms that digest via symbionts Incorrect b. carnivorous animals Incorrect c. tapeworms and other intestinal parasites Incorrect d. rabbits, horses, and herbivorous bears Correct e. humans and other primates Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect b. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct c. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect d. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect e. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of these are involved in the early stages of blood clotting? Choose one answer. a. platelets Correct b. erythropoietin Incorrect c. epinephrine Incorrect d. immunoglobulins Incorrect e. low-density lipoproteins Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following organs is incorrectly paired with its function? Choose one answer. a. stomachprotein digestion Incorrect b. small intestinenutrient absorption Incorrect c. pancreasenzyme production Incorrect d. oral cavitystarch digestion Incorrect e. large intestinebile production Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which process is most directly driven by light energy? Choose one answer. a. reduction of NADP+ molecules Incorrect b. creation of a pH gradient by pumping protons across the thylakoid membrane Incorrect c. ATP synthesis Incorrect d. carbon fixation in the stroma Incorrect e. removal of electrons from chlorophyll molecules Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 A tetrad includes which of the following sets of DNA strands? Choose one answer. a. Two single-stranded chromosomes that have synapsed Incorrect b. Two sets of sister chromatids that have synapsed Correct c. Eight sets of sister chromatids Incorrect d. Four sets of sister chromatids Incorrect e. Four sets of unique chromosomes Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 What is the typical osmolarity of human blood? Choose one answer. a. 500 mosm/L Incorrect b. 30 mosm/L Incorrect c. 100 mosm/L Incorrect d. 200 mosm/L Incorrect e. 300 mosm/L Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. electrons and photons Incorrect b. oxygen and carbon dioxide Incorrect c. water and carbon Incorrect d. carbon dioxide and RuBP Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 In mechanism, photophosphorylation is most similar to Choose one answer. a. reduction of NADP+. Incorrect b. carbon fixation. Incorrect c. oxidative phosphorylation in cellular respiration. Correct d. substrate-level phosphorylation in glycolysis. Incorrect e. the Calvin cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. Choose one answer. a. NaCl crystals will dissolve readily in methanol but will not dissolve in water. Incorrect b. When the first crystals of NaCl are added to water or to methanol, they will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster. Incorrect c. NaCl crystals will dissolve readily in water but will not dissolve in methanol. Correct d. Equal amounts of NaCl crystals will dissolve in both water and methanol. Incorrect e. NaCl crystals will NOT dissolve in either water or methanol. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 The pH of the gastric juice of the stomach is about 2 due to the formation of HCl. Where does this formation of HCl occur? Choose one answer. a. in the secretions of the esophagus Incorrect b. in the parietal cells of the stomach Incorrect c. in the lumen of the stomach Correct d. in the transformation of pepsinogen to pepsin Incorrect e. in the chief cells of the stomach Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. a. the activation energy barrier for this reaction cannot be surmounted. Correct b. the starch solution has less free energy than the sugar solution. Incorrect c. the hydrolysis of starch to sugar is endergonic. Incorrect d. starch hydrolysis is nonspontaneous. Incorrect e. starch cannot be hydrolyzed in the presence of so much water. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. ureter Incorrect b. urethra Incorrect c. juxtamedullary nephrons Correct d. Bowman's capsule Incorrect e. podocytes Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which type of interaction stabilizes the alpha (a) helix and the beta (ß) pleated sheet structures of proteins? Choose one answer. a. nonpolar covalent bonds Incorrect b. peptide bonds Incorrect c. hydrogen bonds Correct d. ionic bonds Incorrect e. hydrophobic interactions Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? Choose one answer. a. Metaphase I of meiosis Incorrect b. Prophase II of meiosis Incorrect c. Anaphase I of meiosis Correct d. Prophase I of meiosis Incorrect e. Anaphase of mitosis Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Through time, the lineage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. This change is best explained by Choose one answer. a. feedback inhibition. Incorrect b. creationism. Incorrect c. the hierarchy of the biological organization of life. Incorrect d. natural philosophy. Incorrect e. natural selection. Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? Choose one answer. a. acetyl CoA Correct b. oxaloacetate Incorrect c. glyceraldehydes-3-phosphate Incorrect d. citrate Incorrect e. lactate Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? Choose one answer. a. connecting enzymes into large aggregates Incorrect b. compartmentalization of enzymes into defined organelles Correct c. cessation of all enzyme formation Incorrect d. exporting enzymes out of the cell Incorrect e. hydrophobic interactions Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Why isn't the mitochondrion classified as part of the endomembrane system? Choose one answer. a. Its structure is not derived from the ER. Correct b. It only has two membrane layers. Incorrect c. It is not involved in protein synthesis. Incorrect d. It has too many vesicles. Incorrect e. It is not attached to the outer nuclear envelope. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. positive feedback. Correct b. a bioinformatic system. Incorrect c. negative feedback. Incorrect d. feedback inhibition. Incorrect e. enzymatic catalysis. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following is a nutritional monomer that can be transported in the blood? Choose one answer. a. sucrose Incorrect b. maltose Incorrect c. fatty acid Correct d. trinucleotide Incorrect e. dipeptide Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Early 19th-century scientists believed that living organisms differed from nonliving things as a result of possessing a "life force" that could create organic molecules from inorganic matter. The term given to this belief is Choose one answer. a. mechanism. Incorrect b. organic evolution. Incorrect c. vitalism. Correct d. organic synthesis. Incorrect e. inorganic synthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 We can be sure that a mole of table sugar and a mole of vitamin C are equal in their Choose one answer. a. number of atoms. Incorrect b. volume. Incorrect c. number of molecules. Correct d. mass in grams. Incorrect e. mass in daltons. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 6 Correct b. 38 Incorrect c. 12 Incorrect d. 2 Incorrect e. 1 Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following is a compartment that often takes up much of the volume of a plant cell? Choose one answer. a. lysosome Incorrect b. Golgi apparatus Incorrect c. mitochondrion Incorrect d. peroxisome Incorrect e. vacuole Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 What is the chromosomal system of sex determination in most species of ants and bees? Choose one answer. a. X-Y Incorrect b. X-0 Incorrect c. Z-W Incorrect d. Haploid-diploid Correct e. X-X Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. There is no possibility of having chemical equilibrium in any living cell. Incorrect b. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect c. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect d. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct e. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Two species that belong to the same genus must also belong to the same Choose one answer. a. class. Incorrect b. phylum. Incorrect c. kingdom. Incorrect d. all of the above Correct e. order. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 In mitochondria, exergonic redox reactions Choose one answer. a. are directly coupled to substrate-level phosphorylation. Incorrect b. are coupled via phosphorylated intermediates to endergonic processes. Incorrect c. provide the energy that establishes the proton gradient. Correct d. reduce carbon atoms to carbon dioxide. Incorrect e. are the source of energy driving prokaryotic ATP synthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Recent evidence shows that individual chromosomes occupy fairly defined territories within the nucleus. Given the structure and location of the following parts of the nucleus, which would be more probably involved in chromosome location? Choose one answer. a. the nucleolus Incorrect b. the nuclear lamina Incorrect c. the outer lipid bilayer Incorrect d. nuclear pores Incorrect e. the nuclear matrix Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Mules are relatively long-lived and hardy organisms that cannot, generally speaking, perform successful meiosis. Consequently, which statement about mules is true? Choose one answer. a. Their offspring have less genetic variation than the parents. Incorrect b. Mutations cannot occur in their genomes. Incorrect c. If crossing-over happens in mules, then it must be limited to prophase of mitosis. Incorrect d. They have a relative evolutionary fitness of zero. Correct e. When two mules interbreed, genetic recombination cannot occur by meiotic crossing over, but only by the act of fertilization. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Rank the following 1-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide: 1. insertion mutation deep within an intron 2. substitution mutation at the 3rd position of an exonic codon 3. substitution mutation at the 2nd position of an exonic codon 4. deletion mutation within the first exon of the gene Choose one answer. a. 2, 1, 4, 3 Incorrect b. 3, 1, 4, 2 Incorrect c. 2, 3, 1, 4 Incorrect d. 1, 2, 3, 4 Incorrect e. 4, 3, 2, 1 Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 When does the synaptonemal complex disappear? Choose one answer. a. Late prophase of meiosis I Correct b. Mid-prophase of meiosis II Incorrect c. During fertilization or fusion of gametes Incorrect d. Early anaphase of meiosis I Incorrect e. Late metaphase of meiosis II Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of Choose one answer. a. ATP, pyruvate, and oxygen. Incorrect b. ATP, CO2, and lactate. Incorrect c. ATP, NADH, and pyruvate. Incorrect d. ATP, pyruvate, and acetyl CoA. Incorrect e. ATP, CO2, and ethanol (ethyl alcohol). Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? Choose one answer. a. Hh Incorrect b. T Incorrect c. HT Correct d. tt Incorrect e. HhTt Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. loop of Henle Correct b. collecting duct Incorrect c. glomerulus Incorrect d. proximal convoluted tubule Incorrect e. Bowman's capsule Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Damage to the sinoatrial node in humans Choose one answer. a. would have a negative effect on peripheral resistance. Incorrect b. is a major contributor to heart attacks. Incorrect c. would disrupt the rate and timing of cardiac muscle contractions. Correct d. would have a direct effect on blood pressure monitors in the aorta. Incorrect e. would block conductance between the bundle branches and the Purkinje fibers. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following would probably contribute to constipation? A substance that Choose one answer. a. contains plenty of fiber. Incorrect b. stimulates peristalsis. Incorrect c. speeds up movement of material in the large intestine. Incorrect d. promotes water reabsorption in the large intestine. Correct e. decreases water reabsorption in the large intestine. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis? Choose one answer. a. 40 Incorrect b. 10 Correct c. 20 Incorrect d. 30 Incorrect e. 80 Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? Choose one answer. a. All organisms use essentially the same genetic code. Correct b. All organisms reproduce. Incorrect c. All organisms require energy. Incorrect d. All organisms show heritable variation. Incorrect e. All organisms have undergone evolution. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 7 Started on Saturday, January 17, 2009, 10:28 AM Completed on Saturday, January 17, 2009, 10:28 AM Time taken 7 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids? Choose one answer. a. contractile vacuole Incorrect b. smooth endoplasmic reticulum Correct c. ribosome Incorrect d. lysosome Incorrect e. mitochondrion Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA? Choose one answer. a. G2 Correct b. S Incorrect c. G0 Incorrect d. G1 Incorrect e. M Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight when denied air. Curiously, the consumption of sugar increases as air is removed from the organism's environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the organism does fine. Which of the following best describes the organism? Choose one answer. a. It is a facultative anaerobe. Correct b. It is a normal eukaryotic organism. Incorrect c. The organism obviously lacks the citric acid cycle and electron transport chain. Incorrect d. It must use a molecule other than oxygen to accept electrons from the electron transport chain. Incorrect e. It is an anaerobic organism. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to Choose one answer. a. add more of the enzyme. Correct b. add an allosteric inhibitor. Incorrect c. add more substrate. Incorrect d. heat the solution to 90°C. Incorrect e. add a noncompetitive inhibitor. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that Choose one answer. a. members of the F1 generation had only one allele for each character, but members of the F2 had two alleles for each character. Incorrect b. the traits were lost in the F1 due to blending of the parental traits. Incorrect c. traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1. Correct d. the mechanism controlling the appearance of traits was different between the F1 and the F2 plants. Incorrect e. new mutations were frequently generated in the F2 progeny, "reinventing" traits that had been lost in the F1. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? Choose one answer. a. oxaloacetate Incorrect b. citrate Incorrect c. glyceraldehydes-3-phosphate Incorrect d. lactate Incorrect e. acetyl CoA Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. From this point in the artery, how many capillary beds must this red blood cell pass through before it returns to the left ventricle of the heart? Choose one answer. a. three Incorrect b. one Incorrect c. four Incorrect d. five Incorrect e. two Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 A cell divides to produce two daughter cells that are genetically different. Choose one answer. a. The statement is true for mitosis and meiosis II. Incorrect b. The statement is true for meiosis I only. Correct c. The statement is true for mitosis and meiosis I. Incorrect d. The statement is true for mitosis only. Incorrect e. The statement is true for meiosis II only. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following statements describes enzyme cooperativity? Choose one answer. a. A multi-enzyme complex contains all the enzymes of a metabolic pathway. Incorrect b. A substrate binds to an active site and inhibits cooperation between enzymes in a pathway. Incorrect c. Several substrate molecules can be catalyzed by the same enzyme. Incorrect d. A substrate molecule bound to an active site affects the active site of several subunits. Correct e. A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from Choose one answer. a. ATP synthase to NADP+ reductase. Incorrect b. the stroma to the photosystem II. Incorrect c. the matrix to the stroma. Incorrect d. the stroma to the thylakoid space. Correct e. the intermembrane space to the matrix. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Large proteins such as albumin remain in capillaries rather than diffusing out. Which of the following does this cause? Choose one answer. a. loss of osmotic pressure in the capillaries Incorrect b. increased diffusion of Hb Incorrect c. creation of an osmotic pressure difference across capillary walls Correct d. increased diffusion of CO2 Incorrect e. loss of fluid from capillaries Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 What is the substrate of salivary amylase? Choose one answer. a. sucrose Incorrect b. maltose Incorrect c. glucose Incorrect d. starch Correct e. protein Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Independent assortment of chromosomes occurs. Choose one answer. a. The statement is true for mitosis and meiosis I. Incorrect b. The statement is true for meiosis II only. Incorrect c. The statement is true for meiosis I only. Correct d. The statement is true for mitosis only. Incorrect e. The statement is true for mitosis and meiosis II. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of his condition? Choose one answer. a. His cells cannot move NADH from glycolysis into the mitochondria. Incorrect b. His cells have a defective electron transport chain, so glucose goes to lactate instead of to acetyl CoA. Incorrect c. His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. Correct d. His cells lack the enzyme in glycolysis that forms pyruvate. Incorrect e. His cells contain something that inhibits oxygen use in his mitochondria. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12M? Choose one answer. a. pH 4 Incorrect b. pH 14 Incorrect c. pH 10 Incorrect d. pH 12 Incorrect e. pH 2 Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which describes brightly colored peacocks mating more frequently than drab peacocks? Choose one answer. a. sexual selection Correct b. artificial selection Incorrect c. stabilizing selection Incorrect d. directional selection Incorrect e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following statements is true about buffer solutions? Choose one answer. a. They maintain a constant pH when bases are added to them but not when acids are added to them. Incorrect b. They maintain a constant pH when acids are added to them but not when bases are added to them. Incorrect c. They maintain a relatively constant pH when either acids or bases are added to them. Correct d. They maintain a constant pH of exactly 7 in all living cells and biological fluids. Incorrect e. They are found only in living systems and biological fluids. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius? Choose one answer. a. 1.0°C Incorrect b. 2.0°C Incorrect c. 0.2°C Incorrect d. 10.0°C Correct e. 20.0°C Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Amino acids are acids because they always possess which functional group? Choose one answer. a. sulfhydryl Incorrect b. amino Incorrect c. carboxyl Correct d. aldehyde Incorrect e. carbonyl Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? Choose one answer. a. The number of phosphates is three instead of one. Incorrect b. The number of phosphates is three instead of two. Incorrect c. There is no difference. Correct d. The nitrogen-containing base is different. Incorrect e. The sugar molecule is different. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways? Choose one answer. a. energy coupling Correct b. bioenergetics Incorrect c. feedback regulation Incorrect d. cooperativity Incorrect e. entropy Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 During aerobic respiration, electrons travel downhill in which sequence? Choose one answer. a. glucose ? pyruvate ? ATP ? oxygen Incorrect b. glucose ? ATP ? electron transport chain ? NADH Incorrect c. food ? citric acid cycle ? ATP ? NAD+ Incorrect d. food ? glycolysis ? citric acid cycle ? NADH ? ATP Incorrect e. food ? NADH ? electron transport chain ? oxygen Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 The dynamics of any ecosystem include the following major processes: Choose one answer. a. the flow of energy from sunlight to producers and then to consumers, and the recycling of chemical nutrients. Correct b. the recycling of chemical nutrients Incorrect c. the flow of energy to producers and the recycling of nutrients Incorrect d. the flow of energy from sunlight to producers and then to consumers Incorrect e. the flow of energy from sunlight to producers Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following processes of osmoregulation by the kidney is the least selective? Choose one answer. a. secretion Incorrect b. filtration Correct c. salt pumping to control osmolarity Incorrect d. reabsorption Incorrect e. H+ pumping to control pH Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect b. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect c. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct d. There is no relationship between the light reactions and the Calvin cycle. Incorrect e. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which cell would be best for studying lysosomes? Choose one answer. a. bacterial cell Incorrect b. leaf cell of a plant Incorrect c. muscle cell Incorrect d. nerve cell Incorrect e. phagocytic white blood cell Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect b. There is no possibility of having chemical equilibrium in any living cell. Incorrect c. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct d. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect e. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Processing of filtrate in the proximal and distal tubules accomplishes what important function? Choose one answer. a. maintaining a constant pH in body fluids Correct b. regulating the speed of blood flow through the nephron Incorrect c. converting toxic ammonia to less toxic urea Incorrect d. reabsorbing urea to maintain osmotic balance Incorrect e. sorting plasma proteins according to size Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following enzymes has the lowest pH optimum? Choose one answer. a. sucrase Incorrect b. lipase Incorrect c. amylase Incorrect d. trypsin Incorrect e. pepsin Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? Choose one answer. a. Small stagnant pools do not provide enough water to dilute the toxic ammonia. Correct b. Urea forms an insoluble precipitate. Incorrect c. Urea takes less energy to synthesize than ammonia. Incorrect d. Urea makes lungfish tissue hypoosmotic to the pool. Incorrect e. The highly toxic urea makes the pool uninhabitable to potential competitors. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 In 1956 Tijo and Levan first successfully counted human chromosomes. The reason it would have taken so many years to have done so would have included all but which of the following? Choose one answer. a. Watson and Crick's structure of DNA was not done until 1953. Correct b. Chromosomes were not distinguishable during interphase. Incorrect c. Chromosomes were piled up on top of one another in the nucleus. Incorrect d. A method had not yet been devised to halt mitosis at metaphase. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? Choose one answer. a. The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. Correct b. The double bonds block interaction among the hydrophilic head groups of the lipids. Incorrect c. Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. Incorrect d. Unsaturated fatty acids permit more water in the interior of the membrane. Incorrect e. The double bonds result in shorter fatty acid tails and thinner membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following statements concerning unsaturated fats is true? Choose one answer. a. They have double bonds in the carbon chains of their fatty acids. Correct b. They generally solidify at room temperature. Incorrect c. They have fewer fatty acid molecules per fat molecule. Incorrect d. They contain more hydrogen than saturated fats having the same number of carbon atoms. Incorrect e. They are more common in animals than in plants. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. an artery Correct b. a portal vessel Incorrect c. a capillary Incorrect d. a venule Incorrect e. a vein Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Bacteria are beneficial to animal nutrition, including that of humans. Which of the following is among their greatest benefits to us? Choose one answer. a. production of vitamins A and C Incorrect b. generation of gases needed for elimination Incorrect c. production of biotin and vitamin K Correct d. recovery of water from fecal matter Incorrect e. absorption of organic materials Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The reaction-center chlorophyll of photosystem I is known as P700 because Choose one answer. a. the plastoquinone reflects light with a wavelength of 700 nm. Incorrect b. this pigment is best at absorbing light with a wavelength of 700 nm. Correct c. there are 700 photosystem I components to each chloroplast. Incorrect d. it absorbs 700 photons per microsecond. Incorrect e. there are 700 chlorophyll molecules in the center. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Cells of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking an enzyme secreted by pancreatic cells. What is its most likely pathway? Choose one answer. a. ER ? Golgi ? vesicles that fuse with plasma membrane Correct b. Golgi ? ER ? lysosome Incorrect c. nucleus ? ER ? Golgi Incorrect d. ER ? Golgi ? nucleus Incorrect e. ER ? lysosomes ? vesicles that fuse with plasma membrane Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of Choose one answer. a. adaptive radiation. Incorrect b. an evolutionary trend. Incorrect c. changes in the Hox gene expression. Incorrect d. paedomorphosis. Incorrect e. exaptation. Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following vitamins is correctly associated with its use? Choose one answer. a. vitamin Kproduction of white blood cells Incorrect b. vitamin Dcalcium removal from bone Incorrect c. vitamin Eprotection of skin from cancer Incorrect d. vitamin Aincorporated into the visual pigment of the eye Correct e. vitamin Ccuring rickets Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype? Choose one answer. a. Early prophase Incorrect b. Late telophase Incorrect c. Late prophase or metaphase Correct d. Anaphase Incorrect e. Late anaphase or early telophase Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism Choose one answer. a. utilizes resources more efficiently than other species occupying similar niches. Incorrect b. lives longer than others of its species. Incorrect c. leaves more viable offspring than others of its species. Correct d. competes for resources more successfully than others of its species. Incorrect e. mates more frequently than others of its species. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following terms best describes when the phenotype of the heterozygote differs from the phenotypes of both homozygotes? Choose one answer. a. Epistasis Incorrect b. Multiple alleles Incorrect c. Pleiotropy Incorrect d. Incomplete dominance Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality could allow which of the following to have a male phenotype? Choose one answer. a. Turner syndrome, 45, X Incorrect b. A person with one normal and one shortened (deleted) X Incorrect c. Translocation of SRY to an autosome of a 46, XX individual Correct d. Down syndrome, 46, XX Incorrect e. A person with too many X chromosomes Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 The theory of evolution is most accurately described as Choose one answer. a. an idea about how acquired characteristics are passed on to subsequent generations. Incorrect b. one possible explanation, among several scientific alternatives, about how species have come into existence. Incorrect c. an overarching explanation, supported by much evidence, for how populations change over time. Correct d. an opinion that some scientists hold about how living things change over time. Incorrect e. an educated guess about how species originate. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. Answer: True False Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? Choose one answer. a. Prophase Incorrect b. Metaphase Correct c. Interphase Incorrect d. Anaphase Incorrect e. Telophase Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Where do air-breathing insects carry out gas exchange? Choose one answer. a. in the alveoli of their lungs Incorrect b. across the thin cuticular exoskeleton Incorrect c. in specialized external gills Incorrect d. in specialized internal gills Incorrect e. across the membranes of cells Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis? Choose one answer. a. chloroplast membranes Incorrect b. nuclear membranes Incorrect c. along the inner surface of the plasma membrane Correct d. free in the cytosol Incorrect e. along the outer edge of the nucleoid Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 One difference between cancer cells and normal cells is that cancer cells Choose one answer. a. cannot function properly because they are affected by density-dependent inhibition. Incorrect b. are always in the M phase of the cell cycle. Incorrect c. are arrested at the S phase of the cell cycle. Incorrect d. are unable to synthesize DNA. Incorrect e. continue to divide even when they are tightly packed together. Correct Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? Choose one answer. a. Protista Incorrect b. Animalia Incorrect c. Fungi Incorrect d. Archaea Correct e. Eukarya Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. carbon dioxide and RuBP Incorrect b. water and carbon Incorrect c. ATP and NADPH Correct d. electrons and photons Incorrect e. oxygen and carbon dioxide Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 In terms of the hierarchical organization of life, a bacterium is at the __________ level of organization, whereas a human is at the __________ level of organization. Choose one answer. a. tissue; organism Incorrect b. single-celled organism; multicellular organism Correct c. organelle; organ system Incorrect d. single organelle; organism Incorrect e. single tissue; multicellular organism Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. Every cell is enclosed by a membrane. Incorrect b. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect c. Every cell uses DNA as its genetic information. Incorrect d. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect e. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In vertebrate animals, brown fat tissue's color is due to abundant mitochondria. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few mitochondria. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue? Choose one answer. a. to increase the production of ATP synthase Incorrect b. to allow other membranes of the cell to perform mitochondrial function Incorrect c. to increase the rate of oxidative phosphorylation from its few mitochondria Incorrect d. to allow the animals to regulate their metabolic rate when it is especially hot Incorrect e. to regulate temperature by converting energy from NADH oxidation to heat Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 How do ADH and RAAS work together in maintaining osmoregulatory homeostasis? Choose one answer. a. Both stimulate the adrenal gland to secrete aldosterone which increases both blood volume and pressure. Incorrect b. Only when they are together in the receptor sites of proximal tubule cells, will reabsorption of essential nutrients back into the blood take place. Incorrect c. ADH an RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS removal of water when it is in excess in body fluids. Incorrect d. ADH monitors osmolarity of the blood and RAAS regulates blood volume. Incorrect e. ADH monitors appropriate osmolarity by reabsorption of water, and RAAS maintains osmolarity by stimulating Na+ reabsorption. Correct Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 The conversion of fibrinogen to fibrin Choose one answer. a. is linked to hypertension and may damage artery walls. Incorrect b. is the final step of a clotting process that involves multiple clotting factors. Correct c. is likely to occur too often in an individual with hemophilia. Incorrect d. occurs within red blood cells. Incorrect e. occurs when fibrinogen is released from broken platelets. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A greater-than-normal volume of isoosmotic urine would be produced. Correct b. A less-than-normal volume of isoosmotic urine would be produced. Incorrect c. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect d. No urine would be produced. Incorrect e. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Who proposed that membranes are a phospholipid bilayer between two layers of hydrophilic proteins? Choose one answer. a. S. Singer and G. Nicolson Incorrect b. E. Gorter and F. Grendel Incorrect c. C. Overton Incorrect d. H. Davson and J. Danielli Correct e. I. Langmuir Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which example below will most likely guarantee that two closely related species will persist only as distinct biological species? Choose one answer. a. convergent evolution Incorrect b. reproductive isolation from one another Correct c. colonization of new habitats Incorrect d. hybridization Incorrect e. geographic isolation from one another Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. gallbladder Incorrect b. stomach Correct c. pancreas Incorrect d. intestine Incorrect e. liver Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 8 Started on Saturday, January 17, 2009, 10:28 AM Completed on Saturday, January 17, 2009, 10:28 AM Time taken 11 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which of the following is considered an open system? Choose one answer. a. liquid in a corked bottle Incorrect b. food cooking in a pressure cooker Incorrect c. a sealed terrarium Incorrect d. an organism Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect b. There is no relationship between the light reactions and the Calvin cycle. Incorrect c. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect d. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect e. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 An explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, insect wings could best be described as Choose one answer. a. exaptations. Correct b. examples of natural selection's predictive ability. Incorrect c. adaptations. Incorrect d. mutations. Incorrect e. isolating mechanisms. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following is predicted in someone who smokes and whose diet includes significant trans fats? Choose one answer. a. increased blood vessel inflammation Correct b. decreased amounts of C-reactive protein secreted by the liver Incorrect c. decreased LDL levels Incorrect d. increased HDL levels Incorrect e. reduced deposition of cholesterol in blood vessels Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? Choose one answer. a. Metaphase Correct b. Interphase Incorrect c. Prophase Incorrect d. Anaphase Incorrect e. Telophase Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following statements is a logical consequence of the second law of thermodynamics? Choose one answer. a. If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. Incorrect b. Energy can be transferred or transformed, but it cannot be created or destroyed. Incorrect c. If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. Incorrect d. Every energy transfer requires activation energy from the environment. Incorrect e. Every chemical reaction must increase the total entropy of the universe. Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 How many structural isomers are possible for a substance having the molecular formula C4H10? Choose one answer. a. 4 Incorrect b. 11 Incorrect c. 3 Incorrect d. 1 Incorrect e. 2 Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald? Choose one answer. a. 33% Incorrect b. 75% Correct c. 50% Incorrect d. 0% Incorrect e. 25% Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which structure-function pair is mismatched? Choose one answer. a. lysosome; intracellular digestion Incorrect b. microtubule; muscle contraction Correct c. ribosome; protein synthesis Incorrect d. nucleolus; production of ribosomal subunits Incorrect e. Golgi; protein trafficking Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs? Choose one answer. a. Gills allow water to flow in one direction Incorrect b. Water contains much less O2 than air per unit volume. Correct c. Water is less dense than air. Incorrect d. Gills allow only unidirectional transport Incorrect e. Gills have less surface area than lungs. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following are nitrogenous bases of the purine type? Choose one answer. a. guanine and adenine Correct b. adenine and thymine Incorrect c. uracil and cytosine Incorrect d. thymine and uracil Incorrect e. cytosine and guanine Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? Choose one answer. a. linear electron flow Incorrect b. cyclic electron flow Correct c. photosystem II Incorrect d. chlorophyll Incorrect e. photosystem I Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 The conversion of fibrinogen to fibrin Choose one answer. a. is the final step of a clotting process that involves multiple clotting factors. Correct b. occurs within red blood cells. Incorrect c. is likely to occur too often in an individual with hemophilia. Incorrect d. is linked to hypertension and may damage artery walls. Incorrect e. occurs when fibrinogen is released from broken platelets. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________. Choose one answer. a. producers; consumers Incorrect b. plants; animals Incorrect c. heat; light Incorrect d. sunlight; heat Correct e. plants; heat Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is Choose one answer. a. the final transfer of electrons to oxygen. Incorrect b. oxidation of glucose to CO2 and water. Incorrect c. the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP. Incorrect d. the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane. Correct e. the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following? Choose one answer. a. The fact that a mutation has occurred Incorrect b. The alleles being codominant Incorrect c. Environmental factors such as soil pH Correct d. The allele for blue hydrangea being completely dominant Incorrect e. Acknowledging that multiple alleles are involved Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis? Choose one answer. a. They have twice the amount of cytoplasm and half the amount of DNA. Incorrect b. They have half the number of chromosomes and one-fourth the amount of DNA. Correct c. They have half the amount of cytoplasm and twice the amount of DNA. Incorrect d. They have the same number of chromosomes and half the amount of DNA. Incorrect e. They have half the number of chromosomes and half the amount of DNA. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? Choose one answer. a. oxidation of pyruvate to acetyl CoA Incorrect b. oxidative phosphorylation (chemiosmosis) Correct c. glycolysis Incorrect d. citric acid cycle Incorrect e. fermentation Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following describes peristalsis in the digestive system? Choose one answer. a. a process of fat emulsification in the small intestine Incorrect b. smooth muscle contractions that move food through the alimentary canal Correct c. a common cause of loss of appetite, fatigue, and dehydration Incorrect d. voluntary control of the rectal sphincters regulating defecation Incorrect e. the transport of nutrients to the liver through the hepatic portal vessel Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Several seriously epidemic viral diseases of earlier centuries were then incurable because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following? Choose one answer. a. antiviral medications that are efficient and work well with all viruses Incorrect b. hydrating drinks that include high concentrations of salts and glucose Correct c. antibiotics against the viruses in question Incorrect d. medication to prevent blood loss Incorrect e. intravenous feeding techniques Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase? Choose one answer. a. It catalyzes the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate, an early step of glycolysis. Incorrect b. It is an allosteric enzyme. Correct c. It is inhibited by citrate, an intermediate of the citric acid cycle. Incorrect d. It is activated by ATP. Incorrect e. It is activated by AMP (derived from ADP). Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Asexual reproduction results in identical offspring unless which of the following occurs? Choose one answer. a. Mutation Correct b. Environmental change Incorrect c. Cloning Incorrect d. Natural selection Incorrect e. Crossing over Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 How does ADH function at the cellular level? Choose one answer. a. It causes an increase in the number of aquaporin molecules of collecting duct cells. Correct b. It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water. Incorrect c. It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. Incorrect d. ADH stimulates the reabsorption of glucose through channel proteins. Incorrect e. It causes membranes to include more phospholipids that have unsaturated fatty acids. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. glycolysis Correct b. oxidative phosphorylation Incorrect c. the citric acid cycle Incorrect d. the oxidation of pyruvate to acetyl CoA Incorrect e. chemiosmosis Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 The element nitrogen is present in all of the following except Choose one answer. a. amino acids. Incorrect b. monosaccharides. Correct c. DNA. Incorrect d. proteins. Incorrect e. nucleic acids. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Rank the following 1-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide: 1. insertion mutation deep within an intron 2. substitution mutation at the 3rd position of an exonic codon 3. substitution mutation at the 2nd position of an exonic codon 4. deletion mutation within the first exon of the gene Choose one answer. a. 1, 2, 3, 4 Incorrect b. 3, 1, 4, 2 Incorrect c. 4, 3, 2, 1 Correct d. 2, 3, 1, 4 Incorrect e. 2, 1, 4, 3 Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect b. protein function at one site affected by binding at another of its active sites Incorrect c. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect d. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect e. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? Choose one answer. a. The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. Incorrect b. The contractile vacuoles used to regulate water content ruptured in the freshwater. Incorrect c. The cells of the sea star dehydrated and lost the ability to metabolize. Incorrect d. The sea star was stressed and needed more time to acclimate to new conditions. Incorrect e. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate. Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a marine shark Incorrect b. a freshwater bony fish Incorrect c. a salmon in freshwater Incorrect d. a marine bony fish Correct e. a shark inhabiting freshwater Lake Nicaragua Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 The dynamics of any ecosystem include the following major processes: Choose one answer. a. the flow of energy from sunlight to producers and then to consumers, and the recycling of chemical nutrients. Correct b. the flow of energy from sunlight to producers Incorrect c. the recycling of chemical nutrients Incorrect d. the flow of energy from sunlight to producers and then to consumers Incorrect e. the flow of energy to producers and the recycling of nutrients Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 An organism with a cell wall would have the most difficulty doing which process? Choose one answer. a. osmosis Incorrect b. phagocytosis Correct c. facilitated diffusion Incorrect d. active transport Incorrect e. diffusion Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 A type of protein critical to all cells is organic catalysts called Choose one answer. a. feedback inhibitors. Incorrect b. nutrients. Incorrect c. feedback activators. Incorrect d. enzymes. Correct e. metabolites. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. The free energy of the system would change. Incorrect b. Additional substrate would be formed. Incorrect c. Additional product would be formed. Incorrect d. Nothing; the reaction would stay at equilibrium. Correct e. The reaction would change from endergonic to exergonic. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe? Choose one answer. a. Genomic imprinting Incorrect b. Chloroplast inheritance Correct c. Infectious inheritance Incorrect d. Mitochondrial inheritance Incorrect e. Sex-linkage Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of Choose one answer. a. allopatric speciation. Incorrect b. habitat selection. Incorrect c. autopolyploidy. Incorrect d. sympatric speciation. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they Choose one answer. a. fix CO2 into pyruvate in the mesophyll cells. Incorrect b. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. Incorrect c. use photosystems I and II at night. Incorrect d. fix CO2 into sugars in the bundle-sheath cells. Incorrect e. fix CO2 into organic acids during the night. Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by Choose one answer. a. van der Waals interactions. Incorrect b. polar covalent bonds. Correct c. ionic bonds. Incorrect d. nonpolar covalent bonds. Incorrect e. hydrogen bonds. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The meshwork that forms the fabric of a blood clot consists mostly of which protein? Choose one answer. a. prothrombin Incorrect b. fibrin Correct c. collagen Incorrect d. fibrinogen Incorrect e. thrombin Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which statement describes the functioning of photosystem II? Choose one answer. a. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. Incorrect b. Light energy excites electrons in the electron transport chain in a photosynthetic unit. Incorrect c. The electron vacancies in P680 are filled by electrons derived from water. Correct d. The splitting of water yields molecular carbon dioxide as a by-product. Incorrect e. The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 When pairs of homologous chromosomes separate during anaphase I, Choose one answer. a. the synaptonemal complex is visible under the light microscope. Incorrect b. the sister chromatids remain attached to one another. Correct c. the maternal chromosomes all move to the same daughter cell. Incorrect d. recombination is not yet complete. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following organs is incorrectly paired with its function? Choose one answer. a. oral cavitystarch digestion Incorrect b. small intestinenutrient absorption Incorrect c. stomachprotein digestion Incorrect d. large intestinebile production Correct e. pancreasenzyme production Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following statements is false for the class of biological molecules known as lipids? Choose one answer. a. They are an important constituent of cell membranes. Incorrect b. They are not true polymers. Incorrect c. They are soluble in water. Correct d. They contain waxes and steroids. Incorrect e. They contain more energy than proteins and carbohydrates. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of these individuals is most likely to be successful in an evolutionary sense? Choose one answer. a. an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce Incorrect b. a male who mates with 20 females and fathers 1 offspring Incorrect c. an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce Correct d. a reproductively sterile individual who never falls ill Incorrect e. a female who mates with 20 males and produces 1 offspring Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Why are C4 plants able to photosynthesize with no apparent photorespiration? Choose one answer. a. They conserve water more efficiently. Incorrect b. They exclude oxygen from their tissues. Incorrect c. They use PEP carboxylase to initially fix CO2. Correct d. They do not participate in the Calvin cycle. Incorrect e. They are adapted to cold, wet climates. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Air rushes into the lungs of humans during inhalation because Choose one answer. a. a positive respiratory pressure is created when the diaphragm relaxes. Incorrect b. gas flows from a region of lower pressure to a region of higher pressure. Incorrect c. the rib muscles and diaphragm contract, increasing the lung volume. Correct d. pressure in the alveoli increases. Incorrect e. pulmonary muscles contract and pull on the outer surface of the lungs. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. proximal tubule Incorrect b. Bowman's capsule Incorrect c. collecting duct Incorrect d. loop of Henle Incorrect e. distal tubules Correct Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 How can one increase the rate of a chemical reaction? Choose one answer. a. Increase the entropy of the reactants. Incorrect b. Increase the activation energy needed. Incorrect c. Add a catalyst. Correct d. Decrease the concentration of the reactants. Incorrect e. Cool the reactants. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Cells of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking an enzyme secreted by pancreatic cells. What is its most likely pathway? Choose one answer. a. ER ? lysosomes ? vesicles that fuse with plasma membrane Incorrect b. Golgi ? ER ? lysosome Incorrect c. ER ? Golgi ? vesicles that fuse with plasma membrane Correct d. ER ? Golgi ? nucleus Incorrect e. nucleus ? ER ? Golgi Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. ADP + Pi Incorrect b. FADH2 Correct c. ATP Incorrect d. NADH Incorrect e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following statements describes pepsin? Choose one answer. a. It begins the hydrolysis of proteins in the stomach. Correct b. It is denatured and rendered inactive in solutions with low pH. Incorrect c. It helps stabilize fat-water emulsions. Incorrect d. It is manufactured by the pancreas. Incorrect e. It splits maltose into monosaccharides. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. a. The Inuit and other peoples in very cold habitats Incorrect b. No groups have such higher frequency Correct c. People in Latin or South America Incorrect d. Very small population groups Incorrect e. People living in equatorial areas of the world Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 The human X and Y chromosomes Choose one answer. a. include only genes that govern sex determination. Incorrect b. are both present in every somatic cell of males and females alike. Incorrect c. include genes that determine an individual's sex. Correct d. are of approximately equal size and number of genes. Incorrect e. are almost entirely homologous, despite their different names. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 About which of these did Darwin have a poor understanding? Choose one answer. a. the sources of genetic variations among individuals Correct b. how a beneficial trait becomes more common in a population over the course of generations Incorrect c. the factors that cause individuals in populations to struggle for survival Incorrect d. that much of the variation between individuals in a population is inherited Incorrect e. that individuals in a population exhibit a good deal of variation Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. selective reabsorption Correct b. secretion Incorrect c. ultrafiltration Incorrect d. filtration Incorrect e. active transport Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. Answer: True False Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 What part(s) of the digestive system have secretions with a pH of 2? Choose one answer. a. stomach Correct b. pancreas Incorrect c. liver Incorrect d. small intestine Incorrect e. mouth Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which is one of the main energy transformers of cells? Choose one answer. a. peroxisome Incorrect b. vacuole Incorrect c. lysosome Incorrect d. mitochondrion Correct e. Golgi apparatus Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection? Choose one answer. a. More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks. Correct b. Small birds mutating their beak genes with the result that later-generation offspring have larger beaks. Incorrect c. Small birds gaining larger beaks by exercising their mouth parts. Incorrect d. Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks. Incorrect e. Larger birds eating less so smaller birds can survive. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this? Choose one answer. a. Epistasis Incorrect b. Pleiotropy Correct c. Incomplete dominance Incorrect d. Multiple alleles Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is hydrolyzed. Incorrect b. The excess is stored as glycogen. Correct c. The excess is oxidized. Incorrect d. The excess is eliminated. Incorrect e. The excess is stored as starch. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 9 Started on Saturday, January 17, 2009, 10:29 AM Completed on Saturday, January 17, 2009, 10:29 AM Time taken 10 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? Choose one answer. a. glyceraldehydes-3-phosphate Incorrect b. lactate Incorrect c. oxaloacetate Incorrect d. acetyl CoA Correct e. citrate Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 The recessive allele that causes phenylketonuria (PKU) is harmful, except when an infant's diet lacks the amino acid, phenylalanine. What maintains the presence of this harmful allele in a population's gene pool? Choose one answer. a. balancing selection Incorrect b. diploidy Correct c. stabilizing selection Incorrect d. heterozygote advantage Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following is true of metabolism in its entirety? Choose one answer. a. Metabolism manages the increase of entropy in an organism Incorrect b. Metabolism depends on an organism's adequate hydration Incorrect c. Metabolism is a property of organismal life Correct d. Metabolism depends on a constant supply of energy from food Incorrect e. Metabolism utilizes all of an organism's resources Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. nitrite Incorrect b. nitrate Incorrect c. uric acid Correct d. ammonia Incorrect e. urea Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 The high osmolarity of the renal medulla is maintained by all of the following except Choose one answer. a. the spatial arrangement of juxtamedullary nephrons. Incorrect b. diffusion of urea from the collecting duct. Incorrect c. active transport of salt from the upper region of the ascending limb. Incorrect d. diffusion of salt from the descending limb of the loop of Henle. Correct e. diffusion of salt from the thin segment of the ascending limb of the loop of Henle. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be Choose one answer. a. to test for production of either sucrose or starch. Incorrect b. to test for liberation of O2 in the light. Correct c. to determine if they have thylakoids in the chloroplasts. Incorrect d. to do experiments to generate an action spectrum. Incorrect e. to test for CO2 fixation in the dark. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. gain of salt through the gills Incorrect b. loss of water in the urine Incorrect c. loss of water through the gills Incorrect d. no drinking of water Incorrect e. gain of water through food Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells? Choose one answer. a. smooth ER Correct b. Nuclear envelope Incorrect c. rough ER Incorrect d. Golgi apparatus Incorrect e. Transport vesicles Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Why are cattle able to survive on a diet consisting almost entirely of plant material? Choose one answer. a. They manufacture all 15 amino acids out of sugars in the liver. Incorrect b. Cattle saliva has enzymes capable of digesting cellulose. Incorrect c. They are autotrophic. Incorrect d. Cattle, like the rabbit, reingest their feces. Incorrect e. They have cellulose-digesting, symbiotic microorganisms in chambers of their stomachs. Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following statements is true of mammals? Choose one answer. a. The epiglottis prevents food from entering the trachea. Correct b. All foods begin their enzymatic digestion in the mouth. Incorrect c. The trachea leads to the esophagus and then to the stomach. Incorrect d. Enzyme production continues in the esophagus. Incorrect e. After leaving the oral cavity, the bolus enters the larynx. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of these provides evidence of the common ancestry of all life? Choose one answer. a. the universality of the genetic code Correct b. the structure of the nucleus Incorrect c. the structure of cilia Incorrect d. the ubiquitous use of catalysts by living systems Incorrect e. the structure of chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald? Choose one answer. a. 75% Correct b. 25% Incorrect c. 0% Incorrect d. 33% Incorrect e. 50% Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis? Choose one answer. a. Disruption of one of these types of structure should necessarily disrupt each of the others as well. Incorrect b. Evolution of motility, of cells or of parts of cells, must have occurred only once. Incorrect c. Motor proteins such as dynein must have evolved before any of these four kinds of structure. Incorrect d. Natural selection for motility must select for microtubular arrays in circular patterns. Correct e. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 How can one increase the rate of a chemical reaction? Choose one answer. a. Cool the reactants. Incorrect b. Add a catalyst. Correct c. Increase the entropy of the reactants. Incorrect d. Decrease the concentration of the reactants. Incorrect e. Increase the activation energy needed. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Why are C4 plants able to photosynthesize with no apparent photorespiration? Choose one answer. a. They do not participate in the Calvin cycle. Incorrect b. They use PEP carboxylase to initially fix CO2. Correct c. They conserve water more efficiently. Incorrect d. They exclude oxygen from their tissues. Incorrect e. They are adapted to cold, wet climates. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The experimental approach taken in current biological investigations presumes that Choose one answer. a. a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods. Incorrect b. living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena. Correct c. living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. Incorrect d. although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods. Incorrect e. simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? Choose one answer. a. There will be no significant difference between these groups. Incorrect b. salt solution the most, water the least Incorrect c. water the most, beer the least Incorrect d. beer the most, water the least Incorrect e. beer the most, salt solution the least Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Birds have negative pressure breathing, but it differs from that of mammals and is more efficient because of which of the following reasons? Choose one answer. a. The flow of air in a bird's lungs is from posterior to anterior. Incorrect b. The maximum PO2 is significantly higher in bird lungs. Correct c. The brain of the bird maximizes oxygen uptake more efficiently. Incorrect d. The bird's mouth movements are able to force air into the lungs. Incorrect e. The tidal volume in birds is much larger than in a comparably sized mammal. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following is a statement of the first law of thermodynamics? Choose one answer. a. The entropy of the universe is decreasing. Incorrect b. Energy cannot be created or destroyed. Correct c. Kinetic energy is stored energy that results from the specific arrangement of matter. Incorrect d. The entropy of the universe is constant. Incorrect e. Energy cannot be transferred or transformed. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? Choose one answer. a. They cover the sensitive chromosomes of the plant. Incorrect b. They reflect orange light. Incorrect c. They take up toxins from the water. Incorrect d. They dissipate excessive light energy. Correct e. They serve as accessory pigments. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 A carbon atom is most likely to form what kind of bond(s) with other atoms? Choose one answer. a. A and B only Incorrect b. covalent Correct c. hydrogen Incorrect d. A, B, and C Incorrect e. ionic Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which definition of evolution would have been most foreign to Charles Darwin during his lifetime? Choose one answer. a. descent with modification Incorrect b. the gradual change of a population's heritable traits over generations Incorrect c. change in gene frequency in gene pools Correct d. populations becoming better adapted to their environments over the course of generations Incorrect e. the appearance of new varieties and new species with the passage of time Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 The method of scientific inquiry that describes natural structures and processes as accurately as possible through careful observation and the analysis of data is known as Choose one answer. a. discovery science. Correct b. experimental science. Incorrect c. qualitative science. Incorrect d. quantitative science. Incorrect e. hypothesis-based science. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur? Choose one answer. a. The action spectrum of that molecule is such that it is different from other molecules of chlorophyll. Incorrect b. The molecular environment lets it boost an electron to a higher energy level and also to transfer the electron to another molecule. Correct c. Each pigment molecule has to be able to act independently to excite electrons. Incorrect d. These chlorophyll a molecules are associated with higher concentrations of ATP. Incorrect e. The potential energy of the electron has to go back to the ground state. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? Choose one answer. a. the release of heat by the breaking of hydrogen bonds Incorrect b. the high surface tension of water Incorrect c. reactions with other atmospheric compounds Incorrect d. the change in density when it condenses to form a liquid or solid Incorrect e. the release of heat by the formation of hydrogen bonds Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean? Choose one answer. a. Cells with proton pumps were maintained in each Kingdom by natural selection. Correct b. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. Incorrect c. Proton pumps are fundamental to all cell types. Incorrect d. Proton pumps must have evolved before any living organisms were present on the earth. Incorrect e. Proton pumps are necessary to all cell membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Which of the following statements is true about buffer solutions? Choose one answer. a. They maintain a constant pH when bases are added to them but not when acids are added to them. Incorrect b. They are found only in living systems and biological fluids. Incorrect c. They maintain a constant pH when acids are added to them but not when bases are added to them. Incorrect d. They maintain a relatively constant pH when either acids or bases are added to them. Correct e. They maintain a constant pH of exactly 7 in all living cells and biological fluids. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 The cyclin component of MPF is destroyed toward the end of this phase: Choose one answer. a. G2 Incorrect b. G1 Incorrect c. S Incorrect d. M Correct e. G0 Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? Choose one answer. a. electron transport Incorrect b. chemiosmosis Incorrect c. the citric acid cycle Incorrect d. glycolysis Correct e. oxidative phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect b. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect c. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct d. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect e. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then Choose one answer. a. hemoglobin will not release oxygen. Incorrect b. most carbon dioxide will be bound to hemoglobin and carried away from tissues. Incorrect c. the pH of the interstitial fluids will increase. Incorrect d. fluids will tend to accumulate in tissues. Correct e. plasma proteins will escape through the endothelium of the capillaries. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is considered an open system? Choose one answer. a. liquid in a corked bottle Incorrect b. a sealed terrarium Incorrect c. an organism Correct d. food cooking in a pressure cooker Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is eliminated. Incorrect b. The excess is stored as starch. Incorrect c. The excess is stored as glycogen. Correct d. The excess is oxidized. Incorrect e. The excess is hydrolyzed. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following statements concerning prokaryotic and eukaryotic cells is not correct? Choose one answer. a. Prokaryotic cells contain small membrane-enclosed organelles. Correct b. Prokaryotic cells lack a membrane-bound nucleus. Incorrect c. Eukaryotic cells contain a membrane-bound nucleus. Incorrect d. DNA or deoxyribonucleic acid is present in the nucleus of eukaryotic cells. Incorrect e. DNA, or deoxyribonucleic acid, is present in both prokaryotic cells and eukaryotic cells. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a Choose one answer. a. higher PCO2. Incorrect b. greater bicarbonate concentration. Incorrect c. lower osmotic pressure. Incorrect d. higher PO2. Correct e. lower pH. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Chromatids are separated from each other. Choose one answer. a. The statement is true for mitosis and meiosis I. Incorrect b. The statement is true for meiosis II only. Incorrect c. The statement is true for mitosis only. Incorrect d. The statement is true for meiosis I only. Incorrect e. The statement is true for mitosis and meiosis II. Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which kind of metabolic poison would most directly interfere with glycolysis? Choose one answer. a. an agent that reacts with oxygen and depletes its concentration in the cell Incorrect b. an agent that binds to pyruvate and inactivates it Incorrect c. an agent that reacts with NADH and oxidizes it to NAD+ Incorrect d. an agent that blocks the passage of electrons along the electron transport chain Incorrect e. an agent that closely mimics the structure of glucose but is not metabolized Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 A major evolutionary episode that corresponds in time most closely with the formation of Pangaea was the Choose one answer. a. Permian extinctions. Correct b. origin of humans. Incorrect c. Cambrian explosion. Incorrect d. Cretaceous extinctions. Incorrect e. Pleistocene ice ages. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of these is a statement that Darwin would have rejected? Choose one answer. a. Natural populations tend to produce more offspring than the environment can support. Incorrect b. Environmental change plays a role in evolution. Incorrect c. Individuals can acquire new characteristics as they respond to new environments or situations. Incorrect d. The smallest entity that can evolve is an individual organism. Correct e. Inherited variation in a population is a necessary precondition for natural selection to operate. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Life is diverse. How many species are estimated to be presently on the earth? Choose one answer. a. 180,000,000 Incorrect b. 1,800,000 Correct c. 18,000,000 Incorrect d. 1,800 Incorrect e. 180,000 Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They have a lot of electrons associated with hydrogen. Correct b. They can have very long carbon skeletons. Incorrect c. They have a lot of oxygen atoms. Incorrect d. They have no nitrogen in their makeup. Incorrect e. They are easily reduced. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ? Choose one answer. a. The appendix might have been larger in fossil hominids. Incorrect b. In a million years, the human species might completely lack an appendix. Incorrect c. The appendix has a substantial amount of defensive lymphatic tissue. Correct d. The appendix can be surgically removed with no immediate ill effects. Incorrect e. Individuals with a larger-than-average appendix leave fewer offspring than those with a below-average-sized appendix. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following organs is incorrectly paired with its function? Choose one answer. a. stomachprotein digestion Incorrect b. oral cavitystarch digestion Incorrect c. small intestinenutrient absorption Incorrect d. pancreasenzyme production Incorrect e. large intestinebile production Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. anaphase Incorrect b. prophase Incorrect c. metaphase Correct d. telophase Incorrect e. prometaphase Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is an enzyme that puts together amino acids to make a protein. Correct b. DNA is a code for the sequence of amino acids in a protein. Incorrect c. Genes are composed of deoxyribonucleic acid. Incorrect d. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect e. DNA is composed of chemical building blocks called nucleotides. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 If a cell has 8 chromosomes at metaphase of mitosis, how many chromosomes will it have during anaphase? Choose one answer. a. 4 Incorrect b. 16 Correct c. 2 Incorrect d. 1 Incorrect e. 8 Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? Choose one answer. a. egg cells (ova), uterus, and kidneys Incorrect b. limbs, hearts, areas with a good deal of contraction Incorrect c. microvilli, alveoli, and glomeruli Incorrect d. all ducts, such as those from salivary or sebaceous glands Incorrect e. sperm, larynx, and trachea Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which is one of the main energy transformers of cells? Choose one answer. a. peroxisome Incorrect b. lysosome Incorrect c. mitochondrion Correct d. Golgi apparatus Incorrect e. vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Altering which of the following levels of structural organization could change the function of a protein? Choose one answer. a. quaternary Incorrect b. primary Incorrect c. tertiary Incorrect d. secondary Incorrect e. all of the above Correct Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that Choose one answer. a. it is possible to obtain large numbers of progeny from any given cross. Incorrect b. peas have an unusually long generation time. Correct c. it is possible to control matings between different pea plants. Incorrect d. many of the observable characters that vary in pea plants are controlled by single genes. Incorrect e. peas show easily observed variations in a number of characters, such as pea shape and flower color. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 If the digestive systems of animals are to provide the energy needed for ATP and biosynthesis, which of the following diets would be most suitable? Choose one answer. a. a high protein, low carbohydrate diet Incorrect b. a diet that matches the "food pyramid" for the species Correct c. a diet that maximizes vitamins and minerals Incorrect d. a low-calorie diet with large intake of fluids, especially water Incorrect e. a diet low in lipids and high in protein Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Nerve and muscle cells are in this phase: Choose one answer. a. M Incorrect b. S Incorrect c. G1 Incorrect d. G2 Incorrect e. G0 Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy (?G = -686 kcal/mol). The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency of cellular respiration for a "mutant" organism that produces only 29 moles of ATP for every mole of glucose oxidized, rather than the usual 36-38 moles of ATP? Choose one answer. a. 0.4% Incorrect b. 30% Correct c. 25% Incorrect d. 60% Incorrect e. 40% Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause? Choose one answer. a. The woman inherited this tendency from her parents. Incorrect b. One member of the couple underwent nondisjunction in somatic cell production. Incorrect c. One member of the couple underwent nondisjunction in gamete production. Correct d. One member of the couple carried a translocation. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? Choose one answer. a. connecting enzymes into large aggregates Incorrect b. hydrophobic interactions Incorrect c. cessation of all enzyme formation Incorrect d. compartmentalization of enzymes into defined organelles Correct e. exporting enzymes out of the cell Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following does not occur during the Calvin cycle? Choose one answer. a. oxidation of NADPH Incorrect b. regeneration of the CO2 acceptor Incorrect c. carbon fixation Incorrect d. release of oxygen Correct e. consumption of ATP Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following? Choose one answer. a. His experiments with the breeding of plants such as peas Correct b. The understanding of particulate inheritance he learned from renowned scientists of his time Incorrect c. His reading of the scientific literature current in the field Incorrect d. His discussions of heredity with his colleagues at major universities Incorrect e. His reading and discussion of Darwin's Origin of Species Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 When a disease is said to have a multifactorial basis, it means that Choose one answer. a. it has many different symptoms. Incorrect b. both genetic and environmental factors contribute to the disease. Correct c. it tends to skip a generation. Incorrect d. it is caused by a gene with a large number of alleles. Incorrect e. it affects a large number of people. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following is not a normal response to increased blood osmolarity in humans? Choose one answer. a. reduced urine production Incorrect b. increased permeability of the collecting duct to water Incorrect c. production of more dilute urine Correct d. increased thirst Incorrect e. release of ADH by the pituitary gland Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have which of the following? Choose one answer. a. hemolymph Incorrect b. branched tracheae Incorrect c. a closed circulatory system Correct d. a gastrovascular cavity Incorrect e. an open circulatory system Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 10 Started on Saturday, January 17, 2009, 10:30 AM Completed on Saturday, January 17, 2009, 10:30 AM Time taken 20 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? Choose one answer. a. anabolism Incorrect b. catalysis Incorrect c. catabolism Correct d. dehydration Incorrect e. metabolism Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 What is true of the fossil record of mammalian origins? Choose one answer. a. It is a good example of punctuated equilibrium. Incorrect b. It includes a series that shows the gradual change of scales into fur. Incorrect c. It shows that mammals and birds evolved from the same kind of dinosaur. Incorrect d. It includes transitional forms with progressively specialized teeth. Correct e. It indicates that mammals and dinosaurs did not overlap in geologic time. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely true? Choose one answer. a. Potassium ions move across the same gradient as sodium ions. Incorrect b. Glucose is entering the cell along its concentration gradient. Incorrect c. A substance that blocked sodium ions from binding to the cotransport protein would also block the transport of glucose. Correct d. Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. Incorrect e. The sodium ions are moving down their electrochemical gradient while glucose is moving up. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus? Choose one answer. a. Earth changed over the years through a series of catastrophic upheavals. Incorrect b. The environment is responsible for natural selection. Incorrect c. All species are fixed in the form in which they are created. Incorrect d. Populations tend to increase at a faster rate than their food supply normally allows. Correct e. Earth is more than 10,000 years old. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 A species has a normal resting systolic blood pressure of >260 mm Hg. What is the most probable hypothesis? Choose one answer. a. The animal is obese. Incorrect b. The species has very wide diameter veins. Incorrect c. The animal is small and does not need the blood pumped far. Incorrect d. The animal has a very long distance between heart and brain. Correct e. The species is characterized by frequent, quick motions. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Evolution is biology's core theme that ties together all the other themes. This is because evolution explains Choose one answer. a. all of the above Correct b. why distantly related organisms sometimes resemble each other. Incorrect c. explains why some organisms have traits in common. Incorrect d. the unity and diversity of life. Incorrect e. how organisms become adapted to their environment through the differential reproductive success of varying individuals. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 What is a hypothesis? Choose one answer. a. a fact based on quantitative data that is falsifiable Incorrect b. the same thing as an unproven theory Incorrect c. a fact based on qualitative data that is testable Incorrect d. a tentative explanation that can be tested and is falsifiable Correct e. a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Cells do not catabolize carbon dioxide because Choose one answer. a. CO2 is already completely oxidized. Correct b. CO2 has fewer bonding electrons than other organic compounds. Incorrect c. CO2 is already completely reduced. Incorrect d. its double bonds are too stable to be broken. Incorrect e. the molecule has too few atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following statements is true of mammals? Choose one answer. a. The trachea leads to the esophagus and then to the stomach. Incorrect b. All foods begin their enzymatic digestion in the mouth. Incorrect c. The epiglottis prevents food from entering the trachea. Correct d. Enzyme production continues in the esophagus. Incorrect e. After leaving the oral cavity, the bolus enters the larynx. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 In glycolysis, for each molecule of glucose oxidized to pyruvate Choose one answer. a. 4 molecules of ATP are used and 2 molecules of ATP are produced. Incorrect b. 2 molecules of ATP are used and 4 molecules of ATP are produced. Correct c. 2 molecules of ATP are used and 6 molecules of ATP are produced. Incorrect d. 2 molecules of ATP are used and 2 molecules of ATP are produced. Incorrect e. 6 molecules of ATP are used and 6 molecules of ATP are produced. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 How is most of the carbon dioxide transported by the blood in humans? Choose one answer. a. CO2 attached to hemoglobin Incorrect b. bicarbonate ions in the plasma Correct c. carbonic acid in the erythrocytes Incorrect d. CO2 dissolved in the plasma Incorrect e. bicarbonate attached to hemoglobin Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following is an advantage of a complete digestive system over a gastrovascular cavity? Choose one answer. a. Intracellular digestion is easier. Incorrect b. Digestive enzymes can be more specific. Incorrect c. Specialized regions are possible. Correct d. Extracellular digestion is not needed. Incorrect e. Extensive branching is possible. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Recent evidence shows that the extracellular matrix can take part in regulating the expression of genes. A likely possibility for this might be which of the following? Choose one answer. a. Fibronectin binds to integrins built into the plasma membrane. Incorrect b. Mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signaling. Correct c. Proteoglycans in the ECM become large enough in aggregate to force genetic alteration. Incorrect d. Intracellular signals might cause changes in the fibronectin binding to the cell surface. Incorrect e. Orientation of microfilaments to the ECM can change the gene activity. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? Choose one answer. a. Urea takes less energy to synthesize than ammonia. Incorrect b. Urea forms an insoluble precipitate. Incorrect c. Small stagnant pools do not provide enough water to dilute the toxic ammonia. Correct d. Urea makes lungfish tissue hypoosmotic to the pool. Incorrect e. The highly toxic urea makes the pool uninhabitable to potential competitors. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur? Choose one answer. a. The potential energy of the electron has to go back to the ground state. Incorrect b. The action spectrum of that molecule is such that it is different from other molecules of chlorophyll. Incorrect c. These chlorophyll a molecules are associated with higher concentrations of ATP. Incorrect d. The molecular environment lets it boost an electron to a higher energy level and also to transfer the electron to another molecule. Correct e. Each pigment molecule has to be able to act independently to excite electrons. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of these is the smallest unit upon which natural selection directly acts? Choose one answer. a. an individual's phenotype Correct b. a population's gene frequency Incorrect c. an individual's genome Incorrect d. an individual's genotype Incorrect e. a species' gene frequency Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called? Choose one answer. a. Duplication Incorrect b. Disjunction Incorrect c. Translocation Correct d. Inversion Incorrect e. Deletion Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 What is the relationship between wavelength of light and the quantity of energy per photon? Choose one answer. a. They have a direct, linear relationship. Incorrect b. They are separate phenomena. Incorrect c. They are only related in certain parts of the spectrum. Incorrect d. They are inversely related. Correct e. They are logarithmically related. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Most cells cannot harness heat to perform work because Choose one answer. a. heat denatures enzymes. Incorrect b. temperature is usually uniform throughout a cell. Correct c. cells do not have much heat; they are relatively cool. Incorrect d. heat can never be used to do work. Incorrect e. heat is not a form of energy. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-forming on either side of the cell plate. This cell is most likely Choose one answer. a. a plant cell in the process of cytokinesis. Correct b. an animal cell in the S phase of the cell cycle. Incorrect c. an animal cell in the process of cytokinesis. Incorrect d. a bacterial cell dividing. Incorrect e. a plant cell in metaphase. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 In which of the following would there be the greatest need for osmoregulation? Choose one answer. a. a terrestrial animal such as a snake Correct b. an animal connective tissue cell bathed in isotonic body fluid Incorrect c. a plant being grown hydroponically (in a watery mixture of designated nutrients) Incorrect d. a lymphocyte before it has been taken back into lymph fluid Incorrect e. a red blood cell surrounded by plasma Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 How is photosynthesis similar in C4 and CAM plants? Choose one answer. a. In both cases, only photosystem I is used. Incorrect b. In both cases, rubisco is not used to fix carbon initially. Correct c. In both cases, thylakoids are not involved in photosynthesis. Incorrect d. Both types of plants make sugar without the Calvin cycle. Incorrect e. Both types of plants make most of their sugar in the dark. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Intracellular digestion of peptides is usually immediately preceded by which process? Choose one answer. a. elimination Incorrect b. endocytosis Correct c. secretion Incorrect d. hydrolysis Incorrect e. absorption Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCL and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be Choose one answer. a. 7.0. Correct b. 5.0. Incorrect c. 9.0. Incorrect d. 12.0. Incorrect e. 2.0. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly Choose one answer. a. embedded in a lipid bilayer. Correct b. spread in a continuous layer over the inner and outer surfaces of the membrane. Incorrect c. free to depart from the fluid membrane and dissolve in the surrounding solution. Incorrect d. confined to the hydrophobic core of the membrane. Incorrect e. randomly oriented in the membrane, with no fixed inside-outside polarity. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy (?G = -686 kcal/mol). The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency of cellular respiration for a "mutant" organism that produces only 29 moles of ATP for every mole of glucose oxidized, rather than the usual 36-38 moles of ATP? Choose one answer. a. 0.4% Incorrect b. 30% Correct c. 25% Incorrect d. 40% Incorrect e. 60% Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Reduction of NADP+ occurs during Choose one answer. a. respiration. Incorrect b. photorespiration. Incorrect c. both photosynthesis and respiration. Incorrect d. neither photosynthesis nor respiration. Incorrect e. photosynthesis. Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long? Choose one answer. a. 8 Incorrect b. 11 Incorrect c. 12 Incorrect d. 9 Incorrect e. 10 Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following is measured by an electrocardiogram? Choose one answer. a. contraction of the two atria Incorrect b. the spread of impulses from the SA node Correct c. systole and diastole Incorrect d. impulses from the AV node Incorrect e. impulses of the parasympathetic nervous system that control heart beat Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 The element nitrogen is present in all of the following except Choose one answer. a. amino acids. Incorrect b. proteins. Incorrect c. monosaccharides. Correct d. nucleic acids. Incorrect e. DNA. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. The reaction would change from endergonic to exergonic. Incorrect b. Additional substrate would be formed. Incorrect c. Additional product would be formed. Incorrect d. Nothing; the reaction would stay at equilibrium. Correct e. The free energy of the system would change. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 What is the mechanism for the production of genetic recombinants? Choose one answer. a. Deletions and duplications during meiosis Incorrect b. X inactivation Incorrect c. Crossing over and independent assortment Correct d. Nondisjunction Incorrect e. Methylation of cytosine Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that Choose one answer. a. peas have an unusually long generation time. Correct b. many of the observable characters that vary in pea plants are controlled by single genes. Incorrect c. peas show easily observed variations in a number of characters, such as pea shape and flower color. Incorrect d. it is possible to obtain large numbers of progeny from any given cross. Incorrect e. it is possible to control matings between different pea plants. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis? Choose one answer. a. Half of the gametes will be n + 1, and half will be n — 1. Incorrect b. All the gametes will be diploid. Incorrect c. Two of the four gametes will be haploid, and two will be diploid. Incorrect d. 1/4 of the gametes will be n + 1, one will be n — 1, and two will be n. Correct e. There will be three extra gametes. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following is true of bile salts? Choose one answer. a. They are normally an ingredient of gastric juice. Incorrect b. They are manufactured by the pancreas. Incorrect c. They are enzymes. Incorrect d. They increase the efficiency of pepsin action. Incorrect e. They emulsify fats in the duodenum. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The MPF protein complex turns itself off by Choose one answer. a. activating a process that destroys cyclin component. Correct b. binding to chromatin. Incorrect c. activating the anaphase-promoting complex. Incorrect d. activating an enzyme that stimulates cyclin. Incorrect e. exiting the cell. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 One of the following people set up a closed system to mimic Earth's early atmosphere and discharged electrical sparks through it. A variety of organic compounds common in organisms were formed. Who did this? Choose one answer. a. Friedrich Wohler Incorrect b. August Kekulé Incorrect c. Jakob Berzelius Incorrect d. Stanley Miller Correct e. Hermann Kolbe Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy? Choose one answer. a. The oxidation of organic compounds can be used to make ATP. Incorrect b. The covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide. Incorrect c. The electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds. Incorrect d. Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O). Correct e. The covalent bond in O2 is unstable and easily broken by electrons from organic molecules. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 The advantage of excreting wastes as urea rather than as ammonia is that Choose one answer. a. urea requires more water for excretion than ammonia. Incorrect b. less nitrogen is removed from the body. Incorrect c. urea can be exchanged for Na+. Incorrect d. urea does not affect the osmolar gradient. Incorrect e. urea is less toxic than ammonia. Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 What is the typical osmolarity of human blood? Choose one answer. a. 30 mosm/L Incorrect b. 100 mosm/L Incorrect c. 500 mosm/L Incorrect d. 200 mosm/L Incorrect e. 300 mosm/L Correct Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's Choose one answer. a. heat content. Incorrect b. endothermic level. Incorrect c. entropy. Incorrect d. activation energy. Correct e. free-energy content. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into Choose one answer. a. kinetic energy. Incorrect b. the potential energy of chemical bonds. Correct c. carbon dioxide and water. Incorrect d. the energy of motion. Incorrect e. oxygen. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The "restriction point" occurs here: Choose one answer. a. S Incorrect b. G2 Incorrect c. G0 Incorrect d. M Incorrect e. G1 Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 An organism has a relatively large number of Hox genes in its genome. Which of the following is not true of this organism? Choose one answer. a. It evolved from evolutionary ancestors that had fewer Hox genes. Incorrect b. It must have multiple paired appendages along the length of its body. Correct c. Its Hox genes cooperated to produce the positional patterns of this organism as it developed. Incorrect d. It has the genetic potential to have a relatively complex anatomy. Incorrect e. At least some of its Hox genes owe their existence to gene duplication events. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Plantae Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Fungi Correct e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Arrange these events from earliest to most recent. 1. emission of lava in what is now Siberia at time of Permian extinctions 2. emission of lava that solidified at the same time as iron-bearing terrestrial rocks began to rust 3. emission of lava that solidified at the same time as rusted iron precipitated from seawater 4. emission of lava in what is now India at time of Cretaceous extinctions Choose one answer. a. 1, 2, 3, 4 Incorrect b. 3, 2, 1, 4 Correct c. 1, 3, 2, 4 Incorrect d. 3, 1, 2, 4 Incorrect e. 3, 1, 4, 2 Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following statements about the 5' end of a polynucleotide strand of DNA is correct? Choose one answer. a. The 5' end is the fifth position on one of the nitrogenous bases. Incorrect b. The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. Incorrect c. The 5' end has a phosphate group attached to the number 5 carbon of ribose. Correct d. The 5' end has a carboxyl group attached to the number 5 carbon of ribose. Incorrect e. The 5' end has thymine attached to the number 5 carbon of ribose. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A freshwater fish was accidentally placed in salt water. After several minutes in this saline water, it died. What is the most logical explanation for its death? Choose one answer. a. The kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment creating an irrevocable loss of homeostasis. Incorrect b. Brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment; death by loss of autonomic function. Incorrect c. Loss of water by osmosis in cells in vital organs resulting in cell death and eventually organ failure. Correct d. Salt diffused into all the fish's cells causing them to swell and, in some cases, lyse. Incorrect e. The gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 To leave the digestive tract, a substance must cross a cell membrane. During which stage of food processing does this take place? Choose one answer. a. absorption Correct b. ingestion Incorrect c. hydrolysis Incorrect d. elimination Incorrect e. digestion Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? Choose one answer. a. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe. Incorrect b. Living organisms do not follow the laws of thermodynamics. Incorrect c. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. Incorrect d. Living organisms are able to transform energy into entropy. Incorrect e. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of Choose one answer. a. 4,000 mL. Incorrect b. 1,450 mL. Incorrect c. 5,000 mL. Correct d. 5,450 mL. Incorrect e. 4,450 mL. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. structure and function Incorrect b. evolution Incorrect c. emergent properties Incorrect d. interaction with the environment Incorrect e. reductionism Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following correctly lists the order in which cellular components will be found in the pellet when homogenized cells are treated with increasingly rapid spins in a centrifuge? Choose one answer. a. nucleus, ribosomes, chloroplasts Incorrect b. vacuoles, ribosomes, nucleus Incorrect c. chloroplasts, ribosomes, vacuoles Incorrect d. ribosomes, nucleus, mitochondria Incorrect e. nucleus, mitochondria, ribosomes Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Why are C4 plants able to photosynthesize with no apparent photorespiration? Choose one answer. a. They conserve water more efficiently. Incorrect b. They use PEP carboxylase to initially fix CO2. Correct c. They are adapted to cold, wet climates. Incorrect d. They do not participate in the Calvin cycle. Incorrect e. They exclude oxygen from their tissues. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. a capillary Incorrect b. an artery Correct c. a vein Incorrect d. a venule Incorrect e. a portal vessel Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following happens at the conclusion of meiosis I? Choose one answer. a. The chromosome number per cell is conserved. Incorrect b. The sperm cells elongate to form a head and a tail end. Incorrect c. Sister chromatids are separated. Incorrect d. Four daughter cells are formed. Incorrect e. Homologous chromosomes are separated. Correct Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 What is the reason that linked genes are inherited together? Choose one answer. a. The number of genes in a cell is greater than the number of chromosomes. Incorrect b. Genes align that way during metaphase I of meiosis. Incorrect c. Alleles are paired together during meiosis. Incorrect d. Chromosomes are unbreakable. Incorrect e. They are located close together on the same chromosome. Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 The ATP made during glycolysis is generated by Choose one answer. a. oxidation of NADH to NAD+. Incorrect b. chemiosmosis. Incorrect c. photophosphorylation. Incorrect d. substrate-level phosphorylation. Correct e. electron transport. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect b. results from active transport. Incorrect c. transfers large molecules as easily as small ones. Incorrect d. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct e. is very selective as to which subprotein sized molecules are transferred. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following describe(s) cyclin-dependent kinase (Cdk)? Choose one answer. a. Both A and B are true. Incorrect b. Both B and C are true. Correct c. Cdk is inactive, or "turned off," in the presence of cyclin. Incorrect d. Cdk is present throughout the cell cycle. Incorrect e. Cdk is an enzyme that attaches phosphate groups to other proteins. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 11 Started on Saturday, January 17, 2009, 10:31 AM Completed on Saturday, January 17, 2009, 10:31 AM Time taken 8 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 The fact that the outer membrane of the nuclear envelope has bound ribosomes allows one to most reliably conclude that Choose one answer. a. nuclear pore complexes contain proteins. Incorrect b. small vesicles from the Golgi fuse with the nuclear envelope. Incorrect c. at least some of the proteins that function in the nuclear envelope are made by the ribosomes on the nuclear envelope. Correct d. the nuclear envelope is not part of the endomembrane system. Incorrect e. the nuclear envelope is physically continuous with the endoplasmic reticulum. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. starch. Incorrect b. fat. Correct c. sugar. Incorrect d. water. Incorrect e. protein. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called? Choose one answer. a. Translocation Correct b. Duplication Incorrect c. Deletion Incorrect d. Disjunction Incorrect e. Inversion Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 No two people are genetically identical, except for identical twins. The chief cause of genetic variation among human individuals is Choose one answer. a. environmental effects. Incorrect b. geographic variation within the population. Incorrect c. the reshuffling of alleles in sexual reproduction. Correct d. genetic drift due to the small size of the population. Incorrect e. new mutations that occurred in the preceding generation. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain? 1. The presence of the herbicide in the environment 2. The absence of the herbicide from the environment 3. The maintenance of the proper conditions for one generation 4. The maintenance of the proper conditions for many generations Choose one answer. a. 1 and 4 Correct b. 2 and 3 Incorrect c. 2 and 4 Incorrect d. 1 and 3 Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect b. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct c. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect d. There is no relationship between the light reactions and the Calvin cycle. Incorrect e. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be Choose one answer. a. 0.25x. Incorrect b. 0.5x. Incorrect c. 2x. Correct d. 4x. Incorrect e. x. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Why is glycolysis described as having an investment phase and a payoff phase? Choose one answer. a. It shifts molecules from cytosol to mitochondrion. Incorrect b. It uses stored ATP and then forms a net increase in ATP. Correct c. It both splits molecules and assembles molecules. Incorrect d. It attaches and detaches phosphate groups. Incorrect e. It uses glucose and generates pyruvate. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 A woman has six sons. The chance that her next child will be a daughter is Choose one answer. a. 1/2. Correct b. 1. Incorrect c. 1/6. Incorrect d. 0. Incorrect e. 5/6. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 A karyotype results from which of the following? Choose one answer. a. The separation of homologous chromosomes at metaphase I of meiosis Incorrect b. A natural cellular arrangement of chromosomes in the nucleus Incorrect c. The ordering of human chromosome images Correct d. The cutting and pasting of parts of chromosomes to form the standard array Incorrect e. An inherited ability of chromosomes to arrange themselves Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. gallbladder Incorrect b. intestine Incorrect c. pancreas Incorrect d. liver Incorrect e. stomach Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. FADH2 Correct b. ADP + Pi Incorrect c. NAD+ Incorrect d. NADH Incorrect e. ATP Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. a. split water and release oxygen to the reaction-center chlorophyll Incorrect b. harvest photons and transfer light energy to the reaction-center chlorophyll Correct c. synthesize ATP from ADP and Pi Incorrect d. transfer electrons to ferredoxin and then NADPH Incorrect e. concentrate photons within the stroma Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. high level of secretion from parietal cells Incorrect b. secretions entering the stomach from the pancreas Incorrect c. high level of secretion by chief cells Incorrect d. mucus secretion and active mitosis of epithelial cells Correct e. a sufficient colony of H. pylori Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. carbon dioxide. Incorrect b. hemoglobin. Correct c. plasma buffers. Incorrect d. carbonic acid. Incorrect e. plasma proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of these is reflective of the hierarchical organization of life from most to least inclusive? Choose one answer. a. kingdom, phylum, class, order, family, genus, species Correct b. genus, species, kingdom, phylum, class, order, family Incorrect c. class, order, kingdom, phylum, family, genus, species Incorrect d. kingdom, order, family, phylum, class, genus, species Incorrect e. phylum, class, order, kingdom, family, genus, species Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Women with Turner syndrome have a genotype characterized as which of the following? Choose one answer. a. aabb Incorrect b. A karyotype of 45, X Correct c. Mental retardation and short arms Incorrect d. A karyotype of 47, XXX Incorrect e. A deletion of the Y chromosome Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Foods eaten by animals are most often composed largely of macromolecules. This requires the animals to have methods for which of the following? Choose one answer. a. elimination Incorrect b. dehydration synthesis Incorrect c. demineralization Incorrect d. enzymatic hydrolysis Correct e. regurgitation Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. The free energy of the system would change. Incorrect b. Additional substrate would be formed. Incorrect c. The reaction would change from endergonic to exergonic. Incorrect d. Additional product would be formed. Incorrect e. Nothing; the reaction would stay at equilibrium. Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 A water sample from a hot thermal vent contained a single-celled organism that had a cell wall but lacked a nucleus. What is its most likely classification? Choose one answer. a. Archaea Correct b. Protista Incorrect c. Eukarya Incorrect d. Animalia Incorrect e. Fungi Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which of the following is most similar in structure to ATP? Choose one answer. a. an RNA nucleotide Correct b. a DNA helix Incorrect c. a phospholipid Incorrect d. an amino acid with three phosphate groups attached Incorrect e. an anabolic steroid Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution? Choose one answer. a. acidic: H+ donor Incorrect b. acidic: H+ acceptor Incorrect c. basic: H+ donor Incorrect d. basic: H+ acceptor Incorrect e. neutral Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 What was the species concept most used by Linnaeus? Choose one answer. a. biological Incorrect b. ecological Incorrect c. phylogenetic Incorrect d. morphological Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Unlike an earthworm's metanephridia, a mammalian nephron Choose one answer. a. forms urine by changing fluid composition inside a tubule. Incorrect b. is intimately associated with a capillary network. Incorrect c. receives filtrate from blood instead of coelomic fluid. Correct d. functions in both osmoregulation and excretion. Incorrect e. has a transport epithelium. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Why is it important that an experiment include a control group? Choose one answer. a. Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor. Correct b. A control group assures that an experiment will be repeatable. Incorrect c. The control group provides a reserve of experimental subjects. Incorrect d. A control group is required for the development of an "if, then" statement. Incorrect e. The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is Choose one answer. a. reinforcement. Incorrect b. fusion. Correct c. geographic isolation. Incorrect d. polyploidy. Incorrect e. stability. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? Choose one answer. a. blood or tissue type of the patient Incorrect b. lack of charge on the drug molecule Incorrect c. similarity of the drug molecule to other molecules transported by the target cells Correct d. non-polarity of the drug molecule Incorrect e. lipid composition of the target cells' plasma membrane Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into Choose one answer. a. carbon dioxide and water. Incorrect b. kinetic energy. Incorrect c. oxygen. Incorrect d. the energy of motion. Incorrect e. the potential energy of chemical bonds. Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of these stimulate the production of red blood cells? Choose one answer. a. platelets Incorrect b. low-density lipoproteins Incorrect c. epinephrine Incorrect d. immunoglobulins Incorrect e. erythropoietin Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced? Choose one answer. a. 10 Incorrect b. 6 Incorrect c. 4 Incorrect d. 5 Incorrect e. 12 Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 An example of a hydrogen bond is the bond between Choose one answer. a. Na+and Cl- in salt. Incorrect b. the H of one water molecule and the O of another water molecule. Correct c. C and H in methane (CH4). Incorrect d. Mg+and Cl- in MgCl2. Incorrect e. the two hydrogen atoms in a molecule of hydrogen gas (H2). Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. reduce FAD+ to FADH2. Incorrect b. reduce NAD+ to NADH. Incorrect c. reduce FADH2 to FAD+. Incorrect d. none of the above Incorrect e. oxidize NADH to NAD+. Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of these speed up heart rate? Choose one answer. a. low-density lipoproteins Incorrect b. platelets Incorrect c. epinephrine Correct d. erythropoietin Incorrect e. immunoglobulins Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following produces and modifies polysaccharides that will be secreted? Choose one answer. a. peroxisome Incorrect b. mitochondrion Incorrect c. Golgi apparatus Correct d. lysosome Incorrect e. vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following is an example of countercurrent exchange? Choose one answer. a. the flow of blood in the dorsal vessel of an insect and that of air within its tracheae Incorrect b. the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins Incorrect c. the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary Incorrect d. the flow of water across the skin of a frog and that of blood within the ventricle of its heart Incorrect e. the flow of water across the gills of a fish and that of blood within those gills Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? Choose one answer. a. simple diffusion Incorrect b. exocytosis Incorrect c. phagocytosis Incorrect d. active transport pumps Incorrect e. facilitated diffusion Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following mechanisms for osmoregulation or nitrogen removal is correctly paired with its corresponding animal? Choose one answer. a. metanephridium-flatworm Incorrect b. kidney-insect Incorrect c. Malpighian tubule-frog Incorrect d. direct cellular exchange-marine invertebrate Correct e. flame bulb-snake Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. a. Very small population groups Incorrect b. No groups have such higher frequency Correct c. The Inuit and other peoples in very cold habitats Incorrect d. People in Latin or South America Incorrect e. People living in equatorial areas of the world Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 The human genome is minimally contained in which of the following? Choose one answer. a. Every human cell Correct b. Each human gene Incorrect c. The entire human population Incorrect d. The entire DNA of a single human Incorrect e. Each human chromosome Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following statements is true of mammals? Choose one answer. a. The epiglottis prevents food from entering the trachea. Correct b. All foods begin their enzymatic digestion in the mouth. Incorrect c. The trachea leads to the esophagus and then to the stomach. Incorrect d. Enzyme production continues in the esophagus. Incorrect e. After leaving the oral cavity, the bolus enters the larynx. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? Choose one answer. a. by increasing the percentage of unsaturated phospholipids in the membrane Correct b. by increasing the percentage of cholesterol molecules in the membrane Incorrect c. by using active transport Incorrect d. by decreasing the number of hydrophobic proteins in the membrane Incorrect e. by co-transport of glucose and hydrogen Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is a false statement concerning amino groups? Choose one answer. a. They are found in amino acids. Incorrect b. They are basic in pH. Incorrect c. They contain nitrogen. Incorrect d. They are components of urea. Incorrect e. They are nonpolar. Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 What is the relationship between wavelength of light and the quantity of energy per photon? Choose one answer. a. They are inversely related. Correct b. They are logarithmically related. Incorrect c. They are only related in certain parts of the spectrum. Incorrect d. They are separate phenomena. Incorrect e. They have a direct, linear relationship. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Choose one answer. a. glycolysis and the oxidation of pyruvate to acetyl CoA Incorrect b. oxidative phosphorylation and fermentation Incorrect c. fermentation and glycolysis Incorrect d. oxidation of pyruvate to acetyl CoA and the citric acid cycle Correct e. the citric acid cycle and oxidative phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Synthesis of ATP by the chemiosmotic mechanism occurs during Choose one answer. a. both photosynthesis and respiration. Correct b. photorespiration. Incorrect c. respiration. Incorrect d. photosynthesis. Incorrect e. neither photosynthesis nor respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 How is most of the carbon dioxide transported by the blood in humans? Choose one answer. a. CO2 dissolved in the plasma Incorrect b. bicarbonate ions in the plasma Correct c. CO2 attached to hemoglobin Incorrect d. carbonic acid in the erythrocytes Incorrect e. bicarbonate attached to hemoglobin Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. distal tubules Correct b. loop of Henle Incorrect c. proximal tubule Incorrect d. collecting duct Incorrect e. Bowman's capsule Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which is a general term for enzymes that activate or inactivate other proteins by phosphorylating them? Choose one answer. a. MPF Incorrect b. Cdk Incorrect c. protein kinase Correct d. PDGF Incorrect e. cyclin Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which group possess excretory structures known as protonephridia? Choose one answer. a. insects Incorrect b. vertebrates Incorrect c. flatworms Correct d. earthworms Incorrect e. cnidarians Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Some bacteria are metabolically active in hot springs because Choose one answer. a. high temperatures make catalysis unnecessary. Incorrect b. they are able to maintain a cooler internal temperature. Incorrect c. their enzymes have high optimal temperatures. Correct d. they use molecules other than proteins or RNAs as their main catalysts. Incorrect e. their enzymes are completely insensitive to temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 We can be sure that a mole of table sugar and a mole of vitamin C are equal in their Choose one answer. a. number of molecules. Correct b. number of atoms. Incorrect c. mass in daltons. Incorrect d. volume. Incorrect e. mass in grams. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 What is the chromosomal system for sex determination in birds? Choose one answer. a. Haploid-diploid Incorrect b. X-X Incorrect c. Z-W Correct d. X-Y Incorrect e. X-0 Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following statements is a logical consequence of the second law of thermodynamics? Choose one answer. a. Every chemical reaction must increase the total entropy of the universe. Correct b. If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. Incorrect c. Every energy transfer requires activation energy from the environment. Incorrect d. If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. Incorrect e. Energy can be transferred or transformed, but it cannot be created or destroyed. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the following is true of a species that has a chromosome number of 2n = 16? Choose one answer. a. Each cell has 8 homologous pairs. Correct b. During the S phase of the cell cycle there will be 32 separate chromosomes. Incorrect c. The species has 16 sets of chromosomes per cell. Incorrect d. A gamete from this species has 4 chromosomes. Incorrect e. The species is diploid with 32 chromosomes per cell. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. both photosynthesis and respiration. Incorrect b. photosynthesis. Incorrect c. photorespiration. Incorrect d. respiration. Incorrect e. neither photosynthesis nor respiration. Correct Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which of the following types of reactions would decrease the entropy within a cell? Choose one answer. a. catabolism Incorrect b. hydrolysis Incorrect c. digestion Incorrect d. dehydration reactions Correct e. respiration Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 What is a hypothesis? Choose one answer. a. a fact based on quantitative data that is falsifiable Incorrect b. the same thing as an unproven theory Incorrect c. a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation Incorrect d. a tentative explanation that can be tested and is falsifiable Correct e. a fact based on qualitative data that is testable Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of these is the smallest unit upon which natural selection directly acts? Choose one answer. a. an individual's genotype Incorrect b. an individual's phenotype Correct c. a species' gene frequency Incorrect d. a population's gene frequency Incorrect e. an individual's genome Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen? Choose one answer. a. a monosaccharide such as glucose Incorrect b. a hydrocarbon such as benzene Incorrect c. an alcohol such as ethanol Incorrect d. an amino acid such as glycine Correct e. a steroid such as testosterone Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? Choose one answer. a. bicarbonate Incorrect b. NaOH Incorrect c. glucose Incorrect d. ammonia Correct e. salt Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 12 Started on Saturday, January 17, 2009, 10:31 AM Completed on Saturday, January 17, 2009, 10:31 AM Time taken 9 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. Answer: True Incorrect False Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? Choose one answer. a. catabolism Correct b. anabolism Incorrect c. dehydration Incorrect d. metabolism Incorrect e. catalysis Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals? Choose one answer. a. The protein of hemocyanin is not bound to metal. Incorrect b. Hemocyanin has protein coupled to copper rather than iron. Correct c. The oxygen dissociation curve for hemocyanin is linear. Incorrect d. Hemocyanin includes cyanic acid. Incorrect e. Hemocyanin carries appreciably more carbon dioxide. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Mendel's second law of independent assortment has its basis in which of the following events of meiosis I? Choose one answer. a. Separation of cells at telophase Incorrect b. Crossing over Incorrect c. Separation of homologs at anaphase Incorrect d. Alignment of tetrads at the equator Correct e. Synapsis of homologous chromosomes Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced? Choose one answer. a. 10 Incorrect b. 4 Incorrect c. 6 Incorrect d. 5 Incorrect e. 12 Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. monomers Correct b. disaccharides Incorrect c. peptides Incorrect d. polymers Incorrect e. enzymes Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 The somatic cells derived from a single-celled zygote divide by which process? Choose one answer. a. replication Incorrect b. mitosis Correct c. meiosis Incorrect d. cytokinesis alone Incorrect e. binary fission Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? Choose one answer. a. The contractile vacuoles used to regulate water content ruptured in the freshwater. Incorrect b. The sea star was stressed and needed more time to acclimate to new conditions. Incorrect c. The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. Incorrect d. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate. Correct e. The cells of the sea star dehydrated and lost the ability to metabolize. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Plantae Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Fungi Correct e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. urethra Incorrect b. podocytes Incorrect c. ureter Incorrect d. Bowman's capsule Incorrect e. juxtamedullary nephrons Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 About which of these did Darwin have a poor understanding? Choose one answer. a. that much of the variation between individuals in a population is inherited Incorrect b. how a beneficial trait becomes more common in a population over the course of generations Incorrect c. the sources of genetic variations among individuals Correct d. that individuals in a population exhibit a good deal of variation Incorrect e. the factors that cause individuals in populations to struggle for survival Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave. What is the most likely explanation for this requirement? Choose one answer. a. Reclining posture during dialysis can cause a tendency for weight gain. Incorrect b. Even small changes in body weight may signify changes in blood volume and therefore blood pressure. Correct c. Many people who have dialysis are diabetic and must control their weight carefully. Incorrect d. Dialysis removes blood proteins and these weigh more than other blood components. Incorrect e. Dialysis is likely to cause edema and such swelling must be controlled. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly Choose one answer. a. spread in a continuous layer over the inner and outer surfaces of the membrane. Incorrect b. free to depart from the fluid membrane and dissolve in the surrounding solution. Incorrect c. randomly oriented in the membrane, with no fixed inside-outside polarity. Incorrect d. embedded in a lipid bilayer. Correct e. confined to the hydrophobic core of the membrane. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of these are involved in the early stages of blood clotting? Choose one answer. a. immunoglobulins Incorrect b. low-density lipoproteins Incorrect c. erythropoietin Incorrect d. platelets Correct e. epinephrine Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. none of the above Incorrect b. reduce NAD+ to NADH. Incorrect c. reduce FADH2 to FAD+. Incorrect d. oxidize NADH to NAD+. Correct e. reduce FAD+ to FADH2. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The advantage of excreting wastes as urea rather than as ammonia is that Choose one answer. a. urea requires more water for excretion than ammonia. Incorrect b. urea can be exchanged for Na+. Incorrect c. urea does not affect the osmolar gradient. Incorrect d. urea is less toxic than ammonia. Correct e. less nitrogen is removed from the body. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Physical anthropologists locating the jaw bones of previously unknown vertebrate animal fossils are often able to assess the animal's diet especially because of clues from which of the following? Choose one answer. a. the prevalence of specific kinds of teeth Correct b. the evidence of food molecules still present Incorrect c. whether the mouth is the most anterior structure Incorrect d. the size of the mouth opening Incorrect e. the position of muscle attachment sites Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle? Choose one answer. a. a gain of NADPH Incorrect b. regeneration of ATP from ADP Incorrect c. regeneration of rubisco Correct d. inactivation of RuBP carboxylase enzyme Incorrect e. addition of a pair of electrons from NADPH Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 The constantly changing nature of the Appalachian ground crickets (Allonemobius fasciatus and Allonemobius socius) hybrid zone favors Choose one answer. a. extinction of both species as the hybrids persist. Correct b. increased levels of gene flow between the two gene pools. Incorrect c. no gene flow between the two gene pools. Incorrect d. little gene flow between the two gene pools. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which of the following statements best summarizes evolution as it is viewed today? Choose one answer. a. It is the differential survival and reproduction of the most-fit phenotypes. Correct b. It is the descent of humans from the present-day great apes. Incorrect c. It is goal-directed. Incorrect d. It is synonymous with the process of gene flow. Incorrect e. It represents the result of selection for acquired characteristics. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which one of the following, if present in a urine sample, would likely be caused by trauma? Choose one answer. a. vitamins Incorrect b. amino acids Incorrect c. glucose Incorrect d. erythrocytes Correct e. salts Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? Choose one answer. a. linear electron flow Incorrect b. cyclic electron flow Correct c. photosystem II Incorrect d. chlorophyll Incorrect e. photosystem I Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. Answer: True False Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are Choose one answer. a. cholesterol molecules. Incorrect b. integral proteins. Correct c. carbohydrates. Incorrect d. phospholipids. Incorrect e. peripheral proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why? Choose one answer. a. Each one both minimizes photorespiration and optimizes the Calvin cycle. Correct b. C4 plants allow less water loss but Cam plants but allow more water loss. Incorrect c. C4 compromises on water loss and CAM compromises on photorespiration. Incorrect d. Each one minimizes both water loss and rate of photosynthesis. Incorrect e. CAM plants allow more water loss, while C4 plants allow less CO2 into the plant. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Pulse is a direct measure of Choose one answer. a. cardiac output. Incorrect b. stroke volume. Incorrect c. breathing rate. Incorrect d. heart rate. Correct e. blood pressure. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Which of the following statements is a logical consequence of the second law of thermodynamics? Choose one answer. a. If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. Incorrect b. Every chemical reaction must increase the total entropy of the universe. Correct c. Every energy transfer requires activation energy from the environment. Incorrect d. Energy can be transferred or transformed, but it cannot be created or destroyed. Incorrect e. If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 RNA molecules can both carry genetic information and be catalytic. This supports the proposal that Choose one answer. a. RNA was the first hereditary information. Correct b. RNA is a polymer of amino acids. Incorrect c. free nucleotides would not have been necessary ingredients in the synthesis of new RNA molecules. Incorrect d. protobionts had an RNA membrane. Incorrect e. RNA could make energy. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should be added to the molecule in order to do so? Choose one answer. a. amino Correct b. sulfhydryl Incorrect c. hydroxyl Incorrect d. phosphate Incorrect e. carboxyl Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 In order for anaphase to begin, which of the following must occur? Choose one answer. a. Cohesin must attach the sister chromatids to each other. Incorrect b. Kinetochores must attach to the metaphase plate. Incorrect c. Chromatids must lose their kinetochores. Incorrect d. Cohesin must be cleaved enzymatically. Correct e. Spindle microtubules must begin to depolymerize. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Altering which of the following levels of structural organization could change the function of a protein? Choose one answer. a. all of the above Correct b. quaternary Incorrect c. primary Incorrect d. tertiary Incorrect e. secondary Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Abnormal chromosomes are frequent in malignant tumors. Errors such as translocations may place a gene in close proximity to different control regions. Which of the following might then occur to make the cancer worse? Choose one answer. a. A decrease in mitotic frequency Incorrect b. An increase in non-disjunction Incorrect c. Sensitivity of the immune system Incorrect d. Expression of inappropriate gene products Correct e. Death of the cancer cells in the tumor Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Choose one answer. a. glycolysis and the oxidation of pyruvate to acetyl CoA Incorrect b. the citric acid cycle and oxidative phosphorylation Incorrect c. oxidative phosphorylation and fermentation Incorrect d. oxidation of pyruvate to acetyl CoA and the citric acid cycle Correct e. fermentation and glycolysis Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. a. Only heterotrophs have mitochondria. Incorrect b. Only heterotrophs require chemical compounds from the environment. Incorrect c. Only heterotrophs require oxygen. Incorrect d. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct e. Cellular respiration is unique to heterotrophs. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend? Choose one answer. a. the enzyme providing an appropriate microenvironment conducive to a reaction's occurrence Incorrect b. the ability of an enzyme to form a template for holding and joining molecules Correct c. the enzyme becoming too saturated because of the concentration of substrate Incorrect d. the enzyme forming covalent bonds with the reactants Incorrect e. the enzyme's ability to stretch reactants and move them toward a transition state Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by Choose one answer. a. the synthesis of lipids and proteins in each of the organelles of the endomembrane system. Incorrect b. the transportation of membrane among the endomembrane system by small membrane vesicles. Incorrect c. the function of the Golgi apparatus in sorting membrane components. Correct d. the modification of the membrane components once they reach their final destination. Incorrect e. the physical separation of most membranes from each other. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes? Choose one answer. a. 460 Incorrect b. 920 Incorrect c. 23 Incorrect d. 46 Incorrect e. About 8 million Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? Choose one answer. a. There will be no significant difference between these groups. Incorrect b. water the most, beer the least Incorrect c. beer the most, salt solution the least Correct d. salt solution the most, water the least Incorrect e. beer the most, water the least Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following is true of bile salts? Choose one answer. a. They are normally an ingredient of gastric juice. Incorrect b. They increase the efficiency of pepsin action. Incorrect c. They emulsify fats in the duodenum. Correct d. They are enzymes. Incorrect e. They are manufactured by the pancreas. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8M? Choose one answer. a. pH 4 Incorrect b. pH 2 Incorrect c. pH 6 Incorrect d. pH 10 Incorrect e. pH 8 Correct Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Enzymes are Choose one answer. a. nucleic acids. Incorrect b. lipids. Incorrect c. proteins. Correct d. carbohydrates. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? Choose one answer. a. Add nitrogen to the soil of the offspring of this plant so the desired traits continue. Incorrect b. Backtrack through her previous experiments to obtain another plant with the same traits. Incorrect c. Force the plant to self-pollinate to obtain an identical one. Incorrect d. Breed this plant with another plant with much weaker traits. Incorrect e. Clone the plant asexually to produce an identical one. Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 What is a karyotype? Choose one answer. a. The set of unique physical characteristics that define an individual Incorrect b. The combination of chromosomes found in a gamete Incorrect c. The collection of all the mutations present within the genome of an individual Incorrect d. A system of classifying cell nuclei Incorrect e. A display of every pair of homologous chromosomes within a cell, organized according to size and shape Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which is one of the main energy transformers of cells? Choose one answer. a. lysosome Incorrect b. vacuole Incorrect c. mitochondrion Correct d. Golgi apparatus Incorrect e. peroxisome Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? Choose one answer. a. hybrid breakdown Incorrect b. gametic isolation Incorrect c. reduced hybrid fertility Incorrect d. habitat isolation Correct e. mechanical isolation Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following about the law of segregation is false? Choose one answer. a. It can be explained by the segregation of homologous chromosomes during meiosis. Incorrect b. It is a method that can be used to determine the number of chromosomes in a plant. Correct c. It can account for the 3:1 ratio seen in the F2 generation of Mendel's crosses. Incorrect d. It can be used to predict the likelihood of transmission of certain genetic diseases within families. Incorrect e. It states that each of two alleles for a given trait segregate into different gametes. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 When applying the process of science, which of these is tested? Choose one answer. a. an observation Incorrect b. a result Incorrect c. a hypothesis Incorrect d. a prediction Correct e. a question Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. glycolysis Correct b. the oxidation of pyruvate to acetyl CoA Incorrect c. chemiosmosis Incorrect d. oxidative phosphorylation Incorrect e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Extracellular compartmentalization of digestive processes is an evolutionary adaptation in many animal phyla. Which of the following phyla is correctly paired with the compartment that first evolved in that phylum? Choose one answer. a. Arthropodastomach Incorrect b. Cnidariagastrovascular cavity Incorrect c. Chordataliver Incorrect d. Molluscalarge intestine Incorrect e. Annelidacomplete alimentary canal Correct Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 A 1:2:1 phenotypic ratio in the F2 generation of a monohybrid cross is a sign of Choose one answer. a. incomplete dominance. Correct b. complete dominance. Incorrect c. pleiotropy. Incorrect d. polygenic inheritance. Incorrect e. multiple alleles. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Without functioning parietal cells, which of the following would you expect for an individual? Choose one answer. a. not to be able to initiate mechanical digestion in the stomach Incorrect b. not to be able to produce pepsinogen Incorrect c. only to be able to digest fat in the stomach Incorrect d. not to be able to initiate digestion in the small intestine. Incorrect e. not to be able to initiate protein digestion in the stomach Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions? Choose one answer. a. Cell membranes do not distinguish the types of ions and molecules passing through them. Incorrect b. Large molecules, especially proteins, do not readily get through one, much less two adjacent cell membranes. Correct c. Cell-to-cell communication requires physical attachment of one cell to another. Incorrect d. Maintenance of connective tissue shape requires cells to adhere to one another. Incorrect e. The relative shapelessness of animal cells requires a mechanism for keeping the cells aligned. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Reduction of NADP+ occurs during Choose one answer. a. both photosynthesis and respiration. Incorrect b. photosynthesis. Correct c. photorespiration. Incorrect d. respiration. Incorrect e. neither photosynthesis nor respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that Choose one answer. a. peas show easily observed variations in a number of characters, such as pea shape and flower color. Incorrect b. peas have an unusually long generation time. Correct c. it is possible to control matings between different pea plants. Incorrect d. it is possible to obtain large numbers of progeny from any given cross. Incorrect e. many of the observable characters that vary in pea plants are controlled by single genes. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 A number of systems for pumping across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Small increases in calcium ions in the cytosol trigger a number of different intracellular reactions, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10-7 in a resting cell, while the concentration in the SR can be 10-2, then how is the ATPase acting? Choose one answer. a. The route of calcium ions must be from SR to the cytosol, to the cell's environment. Incorrect b. The ATP must be powering an inflow of calcium from the outside of the cell into the SR. Incorrect c. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. Correct d. The calcium ions must be diffusing back into the SR along the concentration gradient. Incorrect e. ATP must be transferring Pi to the SR to enable this to occur. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to Choose one answer. a. add a noncompetitive inhibitor. Incorrect b. add more of the enzyme. Correct c. add an allosteric inhibitor. Incorrect d. add more substrate. Incorrect e. heat the solution to 90°C. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? Choose one answer. a. remove lactate from the blood Incorrect b. continue aerobic metabolism when skeletal muscle cannot Correct c. transform lactate to pyruvate again Incorrect d. derive sufficient energy from fermentation Incorrect e. remove oxygen from lactate Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? Choose one answer. a. 100 mL of freshly-brewed coffee Incorrect b. 100 mL of tomato juice Incorrect c. 100 mL of household cleanser containing 0.5M ammonia Correct d. 100 mL of pure water Incorrect e. 100 mL of freshly-squeezed orange juice Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 All the organisms on your campus make up Choose one answer. a. an experimental group. Incorrect b. a community. Correct c. an ecosystem. Incorrect d. a population. Incorrect e. a taxonomic domain. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would be the effect? Choose one answer. a. The heart rate would be decreased. Incorrect b. No apparent effect on heart activity would be observed. Incorrect c. Only the ventricles would contract. Incorrect d. Atria and ventricles would contract at about the same time. Correct e. Only the atria would contract. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 13 Started on Saturday, January 17, 2009, 10:32 AM Completed on Saturday, January 17, 2009, 10:32 AM Time taken 10 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 What was the prevailing notion prior to the time of Lyell and Darwin? Choose one answer. a. Earth is millions of years old, and populations are unchanging. Incorrect b. Earth is a few thousand years old, and populations gradually change. Incorrect c. Earth is millions of years old, and populations rapidly change. Incorrect d. Earth is a few thousand years old, and populations are unchanging. Correct e. Earth is millions of years old, and populations gradually change. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which of the following is true of integral membrane proteins? Choose one answer. a. They are not mobile within the bilayer. Incorrect b. They serve only a structural role in membranes. Incorrect c. They are usually transmembrane proteins. Correct d. They lack tertiary structure. Incorrect e. They are loosely bound to the surface of the bilayer. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. transport protons within the mitochondria and chloroplasts Incorrect b. both oxidize and reduce during electron transport Correct c. donate electrons Incorrect d. act as reducing agents Incorrect e. act as oxidizing agents Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 In a hypothetical environment, fishes called pike-cichlids are visual predators of algae-eating fish (i.e., they locate their prey by sight). If a population of algae-eaters experiences predation pressure from pike-cichlids, which of the following should least likely be observed in the algaeeater population over the course of many generations? Choose one answer. a. Selection for algae-eaters that become sexually mature at smaller overall body sizes Incorrect b. Selection for algae-eaters that are faster swimmers Incorrect c. Selection for nocturnal algae-eaters (active only at night) Incorrect d. Selection for drab coloration of the algae-eaters Incorrect e. Selection for larger female algae-eaters, bearing broods composed of more, and larger, young Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 At sea level, atmospheric pressure is 760 mm Hg. Oxygen gas is approximately 21% of the total gases in the atmosphere. What is the approximate partial pressure of oxygen? Choose one answer. a. 76.0 mm Hg Incorrect b. 0.2 mm Hg Incorrect c. 20.0 mm Hg Incorrect d. 508.0 mm Hg Incorrect e. 160.0 mm Hg Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 When you have a severe fever, what may be a grave consequence if this is not controlled? Choose one answer. a. binding of enzymes to inappropriate substrates Incorrect b. change in the folding of enzymes Correct c. destruction of your enzymes' primary structure Incorrect d. removal of the amino acids in active sites Incorrect e. removal of amine groups from your proteins Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? Choose one answer. a. It could be facing in either direction because the orientation of proteins is scrambled in the Golgi apparatus. Incorrect b. It doesn't matter, because the pump is not active in the ER. Incorrect c. It will be on the side facing the interior of the ER. Incorrect d. It will be on the cytoplasmic side of the ER. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a Choose one answer. a. heterotroph. Incorrect b. CAM plant. Incorrect c. C4 plant. Correct d. chemoautotroph. Incorrect e. C3 plant. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype? Choose one answer. a. Late prophase or metaphase Correct b. Late anaphase or early telophase Incorrect c. Early prophase Incorrect d. Late telophase Incorrect e. Anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Cells do not catabolize carbon dioxide because Choose one answer. a. CO2 is already completely oxidized. Correct b. the molecule has too few atoms. Incorrect c. CO2 is already completely reduced. Incorrect d. its double bonds are too stable to be broken. Incorrect e. CO2 has fewer bonding electrons than other organic compounds. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Enzymes are Choose one answer. a. carbohydrates. Incorrect b. proteins. Correct c. lipids. Incorrect d. nucleic acids. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. loss of water through the gills Incorrect b. gain of salt through the gills Incorrect c. gain of water through food Correct d. loss of water in the urine Incorrect e. no drinking of water Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Most CO2 from catabolism is released during Choose one answer. a. oxidative phosphorylation. Incorrect b. lactate fermentation. Incorrect c. the citric acid cycle. Correct d. electron transport. Incorrect e. glycolysis. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? Choose one answer. a. 4:3 male to female Incorrect b. 1:1 male to female Incorrect c. 1:2 male to female Incorrect d. 3:1 male to female Incorrect e. 2:1 male to female Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? Choose one answer. a. 2 Correct b. 4 Incorrect c. 8 Incorrect d. 6 Incorrect e. 10 Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. muscle proteins Incorrect b. fat stored in adipose tissue Incorrect c. muscle and liver glycogen Correct d. fat stored in the liver Incorrect e. blood proteins Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) is exactly or very approximately equal to item (B). Correct b. Item (A) is less than item (B). Incorrect c. Item (A) may stand in more than one of the above relations to item (B). Incorrect d. Item (A) is greater than item (B). Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 The lowest level of biological organization that can perform all the activities required for life is the Choose one answer. a. organ system–for example, the reproductive system. Incorrect b. organism–for example, an amoeba, dog, human, or maple tree. Incorrect c. organelle–for example, a chloroplast. Incorrect d. tissue–for example, nervous tissue. Incorrect e. cell–for example, a skin cell. Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through Choose one answer. a. gap junctions. Correct b. intermediate filaments. Incorrect c. plasmodesmata. Incorrect d. desmosomes. Incorrect e. tight junctions. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Density-dependent inhibition is explained by which of the following? Choose one answer. a. As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. Incorrect b. As cells become more numerous, more and more of them enter the S phase of the cell cycle. Incorrect c. As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. Incorrect d. As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. Incorrect e. As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Testosterone and estradiol are Choose one answer. a. carbohydrates. Incorrect b. phospholipids. Incorrect c. nucleic acids. Incorrect d. proteins. Incorrect e. steroids. Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. lactate Incorrect b. NADH Correct c. oxygen Incorrect d. pyruvate Incorrect e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 When does the synaptonemal complex disappear? Choose one answer. a. During fertilization or fusion of gametes Incorrect b. Late metaphase of meiosis II Incorrect c. Late prophase of meiosis I Correct d. Mid-prophase of meiosis II Incorrect e. Early anaphase of meiosis I Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Why is it important that an experiment include a control group? Choose one answer. a. The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results. Incorrect b. The control group provides a reserve of experimental subjects. Incorrect c. Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor. Correct d. A control group assures that an experiment will be repeatable. Incorrect e. A control group is required for the development of an "if, then" statement. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following statements is an inference of natural selection? Choose one answer. a. Natural populations tend to reproduce to their full biological potential. Incorrect b. Habitats do not generally have unlimited resources. Incorrect c. Subsequent generations of a population should have greater proportions of individuals that possess traits better suited for success in unchanging environments. Correct d. Some of the variation that exists among individuals in a population is genetic. Incorrect e. An individual organism undergoes evolution over the course of its lifetime. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 In an animal species known for endurance running rather than fast sprinting, which of the following would you expect? Choose one answer. a. a slower rate of oxygen consumption so that its breathing will not have to be accelerated Incorrect b. a much higher rate of oxygen consumption for its size Correct c. a relatively slow heart rate in order to lower oxygen consumption Incorrect d. a lower pressure of oxygen in the alveoli Incorrect e. an increase of storage of oxygen in myoglobin of its muscles Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. nitrite Incorrect b. nitrate Incorrect c. uric acid Correct d. urea Incorrect e. ammonia Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Some bacteria are metabolically active in hot springs because Choose one answer. a. they use molecules other than proteins or RNAs as their main catalysts. Incorrect b. high temperatures make catalysis unnecessary. Incorrect c. they are able to maintain a cooler internal temperature. Incorrect d. their enzymes have high optimal temperatures. Correct e. their enzymes are completely insensitive to temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound? Choose one answer. a. It won't form hydrogen bonds with water. Incorrect b. It should dissolve in a nonpolar solvent. Incorrect c. It lacks an asymmetric carbon, and it is probably a fat or lipid. Incorrect d. It should dissolve in water. Correct e. It is hydrophobic. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which structure-function pair is mismatched? Choose one answer. a. lysosome; intracellular digestion Incorrect b. microtubule; muscle contraction Correct c. nucleolus; production of ribosomal subunits Incorrect d. ribosome; protein synthesis Incorrect e. Golgi; protein trafficking Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe? Choose one answer. a. Chloroplast inheritance Correct b. Genomic imprinting Incorrect c. Mitochondrial inheritance Incorrect d. Sex-linkage Incorrect e. Infectious inheritance Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Where do the enzymatic reactions of the Calvin cycle take place? Choose one answer. a. thylakoid space Incorrect b. stroma of the chloroplast Correct c. outer membrane of the chloroplast Incorrect d. thylakoid membranes Incorrect e. electron transport chain Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which term describes two centrosomes arranged at opposite poles of the cell? Choose one answer. a. metaphase Incorrect b. prophase Incorrect c. prometaphase Correct d. telophase Incorrect e. anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. H2O and NADPH. Incorrect b. sugar and O2. Incorrect c. CO2 and ATP. Incorrect d. ATP and NADPH. Correct e. light energy. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following statements describes pepsin? Choose one answer. a. It is denatured and rendered inactive in solutions with low pH. Incorrect b. It splits maltose into monosaccharides. Incorrect c. It is manufactured by the pancreas. Incorrect d. It helps stabilize fat-water emulsions. Incorrect e. It begins the hydrolysis of proteins in the stomach. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which of the following best describes enthalpy (H)? Choose one answer. a. the total kinetic energy of a system Incorrect b. the system's entropy Incorrect c. the heat content of a chemical system Correct d. the cell's energy equilibrium Incorrect e. the condition of a cell that is not able to react Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes? Choose one answer. a. 75% Incorrect b. 50% Incorrect c. 0% Incorrect d. 25% Incorrect e. 100% Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in Choose one answer. a. pH. Correct b. temperature. Incorrect c. hemoglobin concentration. Incorrect d. the partial pressure of oxygen. Incorrect e. the partial pressure of carbon monoxide. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect b. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect c. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect d. There is no possibility of having chemical equilibrium in any living cell. Incorrect e. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 A chemical reaction that has a positive G is correctly described as Choose one answer. a. exothermic. Incorrect b. enthalpic. Incorrect c. endothermic. Incorrect d. endergonic. Correct e. spontaneous. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. insect Incorrect b. fish Incorrect c. frog Correct d. annelid Incorrect e. mollusc Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following about the law of segregation is false? Choose one answer. a. It can be explained by the segregation of homologous chromosomes during meiosis. Incorrect b. It states that each of two alleles for a given trait segregate into different gametes. Incorrect c. It can account for the 3:1 ratio seen in the F2 generation of Mendel's crosses. Incorrect d. It can be used to predict the likelihood of transmission of certain genetic diseases within families. Incorrect e. It is a method that can be used to determine the number of chromosomes in a plant. Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. a. Theories are hypotheses that have been proved. Incorrect b. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct c. Hypotheses and theories are essentially the same thing. Incorrect d. Hypotheses are guesses; theories are correct answers. Incorrect e. Theories are proved true in all cases; hypotheses are usually falsified by tests. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 What is a hypothesis? Choose one answer. a. a tentative explanation that can be tested and is falsifiable Correct b. a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation Incorrect c. a fact based on qualitative data that is testable Incorrect d. the same thing as an unproven theory Incorrect e. a fact based on quantitative data that is falsifiable Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 How does pyruvate enter the mitochondrion? Choose one answer. a. diffusion Incorrect b. through a pore Incorrect c. through a channel Incorrect d. active transport Correct e. facilitated diffusion Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Speciation Choose one answer. a. proceeds at a uniform tempo across all taxa. Incorrect b. occurs at such a slow pace that no one has ever observed the emergence of new species. Incorrect c. occurs only by the accumulation of genetic change over vast expanses of time. Incorrect d. must begin with the geographic isolation of a small, frontier population. Incorrect e. can involve changes involving a single gene. Correct Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 A localized group of organisms that belong to the same species is called a Choose one answer. a. population. Correct b. family. Incorrect c. ecosystem. Incorrect d. biosystem. Incorrect e. community. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 In which blood vessel is glucose concentration likely to vary the most? Choose one answer. a. pulmonary veins Incorrect b. abdominal artery Incorrect c. hepatic vein, which drains the liver Incorrect d. coronary arteries Incorrect e. hepatic portal vessel Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 A cell divides to produce two daughter cells that are genetically different. Choose one answer. a. The statement is true for mitosis and meiosis I. Incorrect b. The statement is true for meiosis II only. Incorrect c. The statement is true for meiosis I only. Correct d. The statement is true for mitosis and meiosis II. Incorrect e. The statement is true for mitosis only. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Heterozygote advantage should be most closely linked to which of the following? Choose one answer. a. directional selection Incorrect b. disruptive selection Incorrect c. sexual selection Incorrect d. stabilizing selection Correct e. random selection Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Individuals whose diet consists primarily of corn would likely become Choose one answer. a. undernourished. Incorrect b. obese. Incorrect c. anorexic. Incorrect d. overnourished. Incorrect e. malnourished. Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Cells that are in a nondividing state are in which phase? Choose one answer. a. S Incorrect b. G2 Incorrect c. M Incorrect d. G0 Correct e. G1 Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? Choose one answer. a. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate. Correct b. The sea star was stressed and needed more time to acclimate to new conditions. Incorrect c. The cells of the sea star dehydrated and lost the ability to metabolize. Incorrect d. The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. Incorrect e. The contractile vacuoles used to regulate water content ruptured in the freshwater. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. birds. Incorrect b. kangaroo rats. Correct c. desert tortoises. Incorrect d. frogs. Incorrect e. humans. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is stored as glycogen. Correct b. The excess is hydrolyzed. Incorrect c. The excess is stored as starch. Incorrect d. The excess is oxidized. Incorrect e. The excess is eliminated. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 When oxygen is released as a result of photosynthesis, it is a by-product of which of the following? Choose one answer. a. the electron transfer system of photosystem II Incorrect b. the electron transfer system of photosystem I Incorrect c. chemiosmosis Incorrect d. reducing NADP+ Incorrect e. splitting the water molecules Correct Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. Bowman's capsule Incorrect b. loop of Henle Incorrect c. collecting duct Incorrect d. vasa recta Correct e. proximal tubule Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen? Choose one answer. a. lysosome Incorrect b. mitochondrion Incorrect c. peroxisome Correct d. vacuole Incorrect e. Golgi apparatus Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals? Choose one answer. a. Hemocyanin has protein coupled to copper rather than iron. Correct b. The oxygen dissociation curve for hemocyanin is linear. Incorrect c. The protein of hemocyanin is not bound to metal. Incorrect d. Hemocyanin includes cyanic acid. Incorrect e. Hemocyanin carries appreciably more carbon dioxide. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which chemical group is most likely to be responsible for an organic molecule behaving as a base? Choose one answer. a. amino Correct b. hydroxyl Incorrect c. carbonyl Incorrect d. carboxyl Incorrect e. phosphate Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 14 Started on Saturday, January 17, 2009, 10:32 AM Completed on Saturday, January 17, 2009, 10:32 AM Time taken 11 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 The decline of MPF activity at the end of mitosis is due to Choose one answer. a. the destruction of the protein kinase Cdk. Incorrect b. synthesis of DNA. Incorrect c. the degradation of cyclin. Correct d. decreased synthesis of cyclin. Incorrect e. an increase in the cell's volume-to-genome ratio. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 A biologist is studying kidney tubules in small mammals. She wants specifically to examine the juxtaposition of different types of cells in these structures. The cells in question can be distinguished by external shape, size, and 3-dimensional characteristics. Which would be the optimum method for her study? Choose one answer. a. light microscopy using stains specific to kidney function Incorrect b. transmission electron microscopy Incorrect c. light microscopy using living unstained material Incorrect d. cell fractionation Incorrect e. scanning electron microscopy Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H12O6) in cellular respiration? Choose one answer. a. 4 Incorrect b. 38 Incorrect c. 15 Incorrect d. 2 Incorrect e. 76 Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following produces and modifies polysaccharides that will be secreted? Choose one answer. a. Golgi apparatus Correct b. lysosome Incorrect c. mitochondrion Incorrect d. vacuole Incorrect e. peroxisome Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct b. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect c. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect d. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect e. There is no relationship between the light reactions and the Calvin cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The plant's height is 25 centimeters (cm). Incorrect b. The fish swam in a zig-zag motion. Correct c. The temperature decreased from 20°C to 15°C. Incorrect d. The six pairs of robins hatched an average of three chicks. Incorrect e. The contents of the stomach are mixed every 20 seconds. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? Choose one answer. a. They reflect orange light. Incorrect b. They serve as accessory pigments. Incorrect c. They cover the sensitive chromosomes of the plant. Incorrect d. They take up toxins from the water. Incorrect e. They dissipate excessive light energy. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 The element nitrogen is present in all of the following except Choose one answer. a. proteins. Incorrect b. nucleic acids. Incorrect c. DNA. Incorrect d. monosaccharides. Correct e. amino acids. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? Choose one answer. a. HCl Incorrect b. H2CO3 Incorrect c. NH3 Incorrect d. NaCl Incorrect e. NaOH Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following statements describes pepsin? Choose one answer. a. It splits maltose into monosaccharides. Incorrect b. It begins the hydrolysis of proteins in the stomach. Correct c. It helps stabilize fat-water emulsions. Incorrect d. It is manufactured by the pancreas. Incorrect e. It is denatured and rendered inactive in solutions with low pH. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Of the following molecules of the ECM, which is capable of transmitting signals between the ECM and the cytoskeleton? Choose one answer. a. integrins Correct b. collagen Incorrect c. middle lamella Incorrect d. proteoglycans Incorrect e. fibronectin Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. direct exchange of nutrients with the surrounding medium Incorrect b. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect c. a system to circulate gases, nutrients, and wastes to and from cells Correct d. a system of individualized exchange tubules for each cell group Incorrect e. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids? Choose one answer. a. 2012 Correct b. 1220 Incorrect c. 125 Incorrect d. 20 Incorrect e. 412 Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. oxidative phosphorylation Incorrect b. the oxidation of pyruvate to acetyl CoA Incorrect c. glycolysis Correct d. the citric acid cycle Incorrect e. chemiosmosis Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Women with Turner syndrome have a genotype characterized as which of the following? Choose one answer. a. aabb Incorrect b. A karyotype of 47, XXX Incorrect c. A karyotype of 45, X Correct d. Mental retardation and short arms Incorrect e. A deletion of the Y chromosome Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Average blood pressure is lowest in which structure(s)? Choose one answer. a. venae cavae Correct b. the aorta Incorrect c. arterioles Incorrect d. capillaries Incorrect e. arteries Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Intracellular digestion of peptides is usually immediately preceded by which process? Choose one answer. a. hydrolysis Incorrect b. absorption Incorrect c. elimination Incorrect d. endocytosis Correct e. secretion Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which describes brightly colored peacocks mating more frequently than drab peacocks? Choose one answer. a. stabilizing selection Incorrect b. directional selection Incorrect c. sexual selection Correct d. artificial selection Incorrect e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 What is the reason that linked genes are inherited together? Choose one answer. a. Genes align that way during metaphase I of meiosis. Incorrect b. They are located close together on the same chromosome. Correct c. Chromosomes are unbreakable. Incorrect d. The number of genes in a cell is greater than the number of chromosomes. Incorrect e. Alleles are paired together during meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 A hiatal hernia affects the function of the smooth muscle between the esophagus and the stomach. The hernia would be most likely to increase the frequency of which of the following? Choose one answer. a. gastric reflux Correct b. increased stomach pH Incorrect c. retention of food in the stomach Incorrect d. premature entry of food into the duodenum Incorrect e. excess secretion of pepsinogen Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? Choose one answer. a. Genes mutate faster in whales than in humans or bats. Incorrect b. Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. Incorrect c. Whales are not properly classified as mammals. Incorrect d. Forelimb evolution was adaptive in people and bats, but not in whales. Incorrect e. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 During the process of digestion, fats are broken down when fatty acids are detached from glycerol. In addition, proteins are digested to yield amino acids. What do these two processes have in common? Choose one answer. a. They are catalyzed by the same enzyme. Incorrect b. They involve the addition of a water molecule to break bonds (hydrolysis). Correct c. Both require the presence of hydrochloric acid to lower the pH. Incorrect d. Both occur intracellularly in most organisms. Incorrect e. Each requires ATP as an energy source. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. loss of water in the urine Incorrect b. loss of water through the gills Incorrect c. no drinking of water Incorrect d. gain of salt through the gills Incorrect e. gain of water through food Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Organisms categorized as osmoconformers are most likely Choose one answer. a. marine. Correct b. amphibious. Incorrect c. found in arid terrestrial environments. Incorrect d. found in fresh water lakes and streams. Incorrect e. found in terrestrial environments with adequate moisture. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle? Choose one answer. a. The daughter cells have half the number of chromosomes and half the amount of DNA. Incorrect b. The daughter cells have the same number of chromosomes and twice the amount of DNA. Incorrect c. The daughter cells have the same number of chromosomes and half the amount of DNA. Incorrect d. The daughter cells have the same number of chromosomes and the same amount of DNA. Correct e. The daughter cells have half the amount of cytoplasm and half the amount of DNA. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. a portal vessel Incorrect b. a capillary Incorrect c. a venule Incorrect d. a vein Incorrect e. an artery Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. none of the above Incorrect b. reduce NAD+ to NADH. Incorrect c. oxidize NADH to NAD+. Correct d. reduce FAD+ to FADH2. Incorrect e. reduce FADH2 to FAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a Choose one answer. a. lower pH. Incorrect b. higher PO2. Correct c. higher PCO2. Incorrect d. greater bicarbonate concentration. Incorrect e. lower osmotic pressure. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes? Choose one answer. a. a cell that is digesting food particles Incorrect b. a cell that is secreting proteins Incorrect c. a cell that is enlarging its vacuole Incorrect d. a cell that is constructing its cell wall or extracellular matrix Incorrect e. a cell that is producing cytoplasmic enzymes Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? Choose one answer. a. ecological Incorrect b. phylogenetic Incorrect c. morphological Incorrect d. biological Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following are directly associated with photosystem I? Choose one answer. a. receiving electrons from plastocyanin Correct b. extraction of hydrogen electrons from the splitting of water Incorrect c. passing electrons to plastoquinone Incorrect d. P680 reaction-center chlorophyll Incorrect e. harvesting of light energy by ATP Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following are nitrogenous bases of the purine type? Choose one answer. a. cytosine and guanine Incorrect b. guanine and adenine Correct c. adenine and thymine Incorrect d. thymine and uracil Incorrect e. uracil and cytosine Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level? Choose one answer. a. cell, community, population, organ system, molecule, organelle Incorrect b. organism, community, biosphere, molecule, tissue, organ Incorrect c. organelle, tissue, biosphere, ecosystem, population, organism Incorrect d. molecule, cell, organ system, population, ecosystem, biosphere Correct e. ecosystem, cell, population, tissue, organism, organ system Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. Answer: True False Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following types of reactions would decrease the entropy within a cell? Choose one answer. a. catabolism Incorrect b. digestion Incorrect c. dehydration reactions Correct d. respiration Incorrect e. hydrolysis Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Fossilized stromatolites Choose one answer. a. formed around deep-sea vents. Incorrect b. contain the first undisputed fossils of eukaryotes and date from 2.1 billion years ago. Incorrect c. provide evidence that plants moved onto land in the company of fungi around 500 million years ago. Incorrect d. resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays. Correct e. all date from 2.7 billion years ago. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following is most similar in structure to ATP? Choose one answer. a. an RNA nucleotide Correct b. an anabolic steroid Incorrect c. a phospholipid Incorrect d. a DNA helix Incorrect e. an amino acid with three phosphate groups attached Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? Choose one answer. a. protein kinase Incorrect b. PDGF Incorrect c. MPF Incorrect d. Cdk Incorrect e. cyclin Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? Choose one answer. a. archaea Correct b. fungi Incorrect c. animal Incorrect d. plant Incorrect e. protists Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. proximal tubule Incorrect b. Bowman's capsule Incorrect c. collecting duct Incorrect d. distal tubules Correct e. loop of Henle Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from Choose one answer. a. the matrix to the stroma. Incorrect b. the intermembrane space to the matrix. Incorrect c. the stroma to the thylakoid space. Correct d. the stroma to the photosystem II. Incorrect e. ATP synthase to NADP+ reductase. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to Choose one answer. a. disruption of mitotic spindle formation. Correct b. inhibition of regulatory protein phosphorylation. Incorrect c. inhibition of DNA synthesis. Incorrect d. suppression of cyclin production. Incorrect e. myosin denaturation and inhibition of cleavage furrow formation. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? Choose one answer. a. energy released from movement of protons through ATP synthase Correct b. energy released as electrons flow through the electron transport system Incorrect c. energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix Incorrect d. No external source of energy is required because the reaction is exergonic. Incorrect e. energy released from substrate-level phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 On food packages, to what does the term "insoluble fiber" refer? Choose one answer. a. cellulose Correct b. polypeptides Incorrect c. starch Incorrect d. chitin Incorrect e. amylopectin Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 An animal that migrates great distances would obtain the greatest benefit from storing its energy as Choose one answer. a. proteins. Incorrect b. minerals. Incorrect c. fats. Correct d. carbohydrates. Incorrect e. amino acids. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect b. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect c. Every cell is enclosed by a membrane. Incorrect d. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct e. Every cell uses DNA as its genetic information. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 The body fluids of an osmoconformer would be __________ with its __________ environment. Choose one answer. a. hypoosmotic; saltwater Incorrect b. hyperosmotic; freshwater Incorrect c. isoosmotic; saltwater Correct d. isotonic; freshwater Incorrect e. hyperosmotic; saltwater Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which of the following statements about genes is incorrect? Choose one answer. a. Many genes contain the information needed for cells to synthesize enzymes and other proteins. Incorrect b. During fertilization, both the sperm and the ovum contribute genes to the resulting fertilized egg. Incorrect c. One gene only is used in a specific cell type. Correct d. Genetic differences can result from changes in the DNA called mutations. Incorrect e. Genes correspond to segments of DNA. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a[[no]] Choose one answer. a. four-chambered heart. Correct b. lymphatic system. Incorrect c. two-chambered heart. Incorrect d. hemocoel. Incorrect e. open circulatory system. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? Choose one answer. a. The pH of the stroma is higher than that of the other two measurements. Incorrect b. The pH of the thylakoid space is higher than that anywhere else in the cell. Incorrect c. The pH within the thylakoid is less than that of the stroma. Correct d. There is no consistent relationship. Incorrect e. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 The same gene that causes various coat patterns in wild and domesticated cats also causes the cross-eyed condition in these cats, the cross-eyed condition being slightly maladaptive. In a hypothetical environment, the coat pattern that is associated with crossed eyes is highly adaptive, with the result that both the coat pattern and the cross-eyed condition increase in a feline population over time. Which statement is supported by these observations? Choose one answer. a. Polygenic inheritance is generally maladaptive, and should become less common in future generations. Incorrect b. Natural selection reduces the frequency of maladaptive genes in populations over the course of time. Incorrect c. In all environments, coat pattern is a more important survival factor than is eye-muscle tone. Incorrect d. Evolution is progressive and tends toward a more perfect population. Incorrect e. Phenotype is often the result of compromise. Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Choose one answer. a. oxidative phosphorylation and fermentation Incorrect b. fermentation and glycolysis Incorrect c. the citric acid cycle and oxidative phosphorylation Incorrect d. glycolysis and the oxidation of pyruvate to acetyl CoA Incorrect e. oxidation of pyruvate to acetyl CoA and the citric acid cycle Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following about the law of segregation is false? Choose one answer. a. It states that each of two alleles for a given trait segregate into different gametes. Incorrect b. It can be explained by the segregation of homologous chromosomes during meiosis. Incorrect c. It can account for the 3:1 ratio seen in the F2 generation of Mendel's crosses. Incorrect d. It is a method that can be used to determine the number of chromosomes in a plant. Correct e. It can be used to predict the likelihood of transmission of certain genetic diseases within families. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 How does ADH function at the cellular level? Choose one answer. a. It causes membranes to include more phospholipids that have unsaturated fatty acids. Incorrect b. It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. Incorrect c. ADH stimulates the reabsorption of glucose through channel proteins. Incorrect d. It causes an increase in the number of aquaporin molecules of collecting duct cells. Correct e. It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. a. The energy content of an organism is constant. Incorrect b. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct c. Organisms are unable to transform energy. Incorrect d. Life does not obey the first law of thermodynamics. Incorrect e. The entropy of an organism decreases with time as the organism grows in complexity. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? Choose one answer. a. denaturization of the enzyme Incorrect b. insufficient cofactors Incorrect c. competitive inhibition Correct d. allosteric inhibition Incorrect e. saturation of the enzyme activity Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? Choose one answer. a. n + 1; n - 1; n; n Incorrect b. n + 1; n - 1; n - 1; n - 1 Incorrect c. n + 1; n + 1; n; n Incorrect d. n + 1; n + 1; n - 1; n - 1 Correct e. n - 1; n - 1; n; n Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype? Choose one answer. a. Enlarged genital structures Incorrect b. Normal female Correct c. Sterile female Incorrect d. Masculine characteristics such as facial hair Incorrect e. Excessive emotional instability Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? Choose one answer. a. It will be on the cytoplasmic side of the ER. Correct b. It could be facing in either direction because the orientation of proteins is scrambled in the Golgi apparatus. Incorrect c. It doesn't matter, because the pump is not active in the ER. Incorrect d. It will be on the side facing the interior of the ER. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell? Choose one answer. a. It can enter the nucleus to affect gene expression. Incorrect b. It is released as an excretory waste. Incorrect c. It can be added to other molecules in order to activate them. Correct d. It can be added to water and excreted as a liquid. Incorrect e. It can only be used to regenerate more ATP. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 15 Started on Saturday, January 17, 2009, 10:33 AM Completed on Saturday, January 17, 2009, 10:33 AM Time taken 8 secs Raw score 1/60 (2%) Grade out of a maximum of Question 1 Marks: 1 Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? Choose one answer. a. the synthesis of ATP Correct b. the reduction of NADP+ Incorrect c. the splitting of water Incorrect d. the flow of electrons from photosystem II to photosystem I Incorrect e. the absorption of light energy by chlorophyll Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this? Choose one answer. a. an animal cell in metaphase Incorrect b. a plant cell undergoing cytokinesis Correct c. an animal cell undergoing cytokinesis Incorrect d. an animal cell in telophase Incorrect e. a plant cell in metaphase Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. Nothing; the reaction would stay at equilibrium. Correct b. The free energy of the system would change. Incorrect c. Additional product would be formed. Incorrect d. The reaction would change from endergonic to exergonic. Incorrect e. Additional substrate would be formed. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 What is the typical osmolarity of human blood? Choose one answer. a. 100 mosm/L Incorrect b. 300 mosm/L Correct c. 30 mosm/L Incorrect d. 200 mosm/L Incorrect e. 500 mosm/L Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Whether during mitosis or meiosis, sister chromatids are held together by proteins referred to as cohesions. Such molecules must have which of the following properties? Choose one answer. a. They must be removed before anaphase can occur. Correct b. They must be removed before meiosis can begin. Incorrect c. They must be intact for nuclear envelope reformation. Incorrect d. They must persist throughout the cell cycle. Incorrect e. They must reattach to chromosomes during G1. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. bringing glucose and fructose together to form sucrose. Incorrect b. the release of water from sucrose as the bond between glucose and fructose is broken. Incorrect c. utilization of water as a covalent bond is formed between glucose and fructose to form sucrase. Incorrect d. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct e. production of water from the sugar as bonds are broken between the glucose monomers. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Tidal volume in respiration is analogous to what measurement in cardiac physiology? Choose one answer. a. systolic pressure Incorrect b. diastolic pressure Incorrect c. cardiac output Incorrect d. stroke volume Correct e. heart rate Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. active transport Incorrect b. ultrafiltration Incorrect c. filtration Incorrect d. selective reabsorption Correct e. secretion Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. frogs. Incorrect b. birds. Incorrect c. humans. Incorrect d. desert tortoises. Incorrect e. kangaroo rats. Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following minerals is associated with its use in animals? Choose one answer. a. iodineimportant in nerve function Incorrect b. magnesiumcofactor in enzymes that make ATP Incorrect c. sulfuringredient of nucleic acids Incorrect d. calciumconstruction and maintenance of bone Correct e. ironnecessary for thyroid function Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of Choose one answer. a. 5,450 mL. Incorrect b. 5,000 mL. Correct c. 1,450 mL. Incorrect d. 4,000 mL. Incorrect e. 4,450 mL. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Average blood pressure is lowest in which structure(s)? Choose one answer. a. capillaries Incorrect b. arterioles Incorrect c. venae cavae Correct d. arteries Incorrect e. the aorta Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle? Choose one answer. a. regeneration of ATP from ADP Incorrect b. inactivation of RuBP carboxylase enzyme Incorrect c. regeneration of rubisco Correct d. a gain of NADPH Incorrect e. addition of a pair of electrons from NADPH Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 A controlled experiment is one that Choose one answer. a. may include experimental groups and control groups tested in parallel. Correct b. is supervised by an experienced scientist. Incorrect c. is repeated many times to make sure the results are accurate. Incorrect d. proceeds slowly enough that a scientist can make careful records of the results. Incorrect e. keeps all environmental variables constant. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 The lowest level of biological organization that can perform all the activities required for life is the Choose one answer. a. organism–for example, an amoeba, dog, human, or maple tree. Incorrect b. tissue–for example, nervous tissue. Incorrect c. organ system–for example, the reproductive system. Incorrect d. organelle–for example, a chloroplast. Incorrect e. cell–for example, a skin cell. Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. high level of secretion from parietal cells Incorrect b. secretions entering the stomach from the pancreas Incorrect c. mucus secretion and active mitosis of epithelial cells Correct d. a sufficient colony of H. pylori Incorrect e. high level of secretion by chief cells Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following is likely to lead to an increase in the concentration of ATP in a cell? Choose one answer. a. an increase in a cell's anabolic activity Incorrect b. an increase in a cell's catabolic activity Correct c. the cell's increased transport of materials to the environment Incorrect d. an increased amino acid concentration Incorrect e. an increased influx of cofactor molecules Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 The presence of cholesterol in the plasma membranes of some animals Choose one answer. a. enables the animal to add hydrogen atoms to unsaturated phospholipids. Incorrect b. enables the animal to remove hydrogen atoms from saturated phospholipids. Incorrect c. enables the membrane to stay fluid more easily when cell temperature drops. Correct d. makes the animal more susceptible to circulatory disorders. Incorrect e. makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to Choose one answer. a. inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle. Incorrect b. inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Correct c. activate the enzyme and increase the rates of glycolysis and the citric acid cycle. Incorrect d. activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Incorrect e. inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which is a true statement concerning genetic variation? Choose one answer. a. It arises in response to changes in the environment. Incorrect b. It must be present in a population before natural selection can act upon the population. Correct c. It is created by the direct action of natural selection. Incorrect d. It tends to be reduced by the processes involved when diploid organisms produce gametes. Incorrect e. A population that has a higher average heterozygosity has less genetic variation than one with a larger average heterozygosity. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? Choose one answer. a. on the outer surface of the nucleus Incorrect b. on the inside surface of the vesicle Correct c. on the outside of vesicles Incorrect d. on the ER Incorrect e. on the inside surface of the cell membrane Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Women with Turner syndrome have a genotype characterized as which of the following? Choose one answer. a. A karyotype of 47, XXX Incorrect b. aabb Incorrect c. A deletion of the Y chromosome Incorrect d. Mental retardation and short arms Incorrect e. A karyotype of 45, X Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism Choose one answer. a. competes for resources more successfully than others of its species. Incorrect b. mates more frequently than others of its species. Incorrect c. utilizes resources more efficiently than other species occupying similar niches. Incorrect d. lives longer than others of its species. Incorrect e. leaves more viable offspring than others of its species. Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population? Choose one answer. a. disruptive selection Incorrect b. directional selection Correct c. sexual selection Incorrect d. No selection would operate because the population is in Hardy-Weinberg equilibrium. Incorrect e. stabilizing selection Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 PKU (phenylketonuria) is a hereditary condition in which infants and young children cannot ingest any more than tiny amounts of the amino acid phenylalanine without serious neurological results. This damage can be prevented by a severe restriction of phenylalanine in the diet. Which of the following is the nutritional concept that forms the basis for this preventive treatment? Choose one answer. a. enzymatic hydrolysis Incorrect b. dehydration synthesis Incorrect c. symbiosis Incorrect d. structural anatomy of the brain Incorrect e. essential nutrients Correct Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Microbial symbionts are especially important for nutritional support in which of the following? Choose one answer. a. animals without an esophagus Incorrect b. carnivores and omnivores Incorrect c. animals with large stomach and short intestines Incorrect d. herbivores and carnivores Incorrect e. herbivores and omnivores Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, taxol must affect Choose one answer. a. anaphase. Incorrect b. chromatid assembly. Incorrect c. formation of the centrioles. Incorrect d. the fibers of the mitotic spindle. Correct e. the S phase of the cell cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 A common form of regulation in which accumulation of an end product of a process slows that process is called positive feedback. Answer: True False Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of these are attached to the extracellular matrix? Choose one answer. a. integrins Correct b. integral proteins Incorrect c. transmembrane proteins Incorrect d. glycoproteins Incorrect e. peripheral proteins Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype? Choose one answer. a. Normal female Correct b. Excessive emotional instability Incorrect c. Sterile female Incorrect d. Enlarged genital structures Incorrect e. Masculine characteristics such as facial hair Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Air rushes into the lungs of humans during inhalation because Choose one answer. a. pulmonary muscles contract and pull on the outer surface of the lungs. Incorrect b. gas flows from a region of lower pressure to a region of higher pressure. Incorrect c. a positive respiratory pressure is created when the diaphragm relaxes. Incorrect d. pressure in the alveoli increases. Incorrect e. the rib muscles and diaphragm contract, increasing the lung volume. Correct Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 One of two major forms of a human condition called neurofibromatosis (NF 1) is inherited as a dominant, although it may be either mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation? Choose one answer. a. The condition skipped a generation in the family. Incorrect b. One of the parents has very mild expression of the gene. Correct c. The mother carries the gene but does not express it at all. Incorrect d. The child has a different allele of the gene than the parents. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 According to the induced fit hypothesis of enzyme catalysis, which of the following is correct? Choose one answer. a. A competitive inhibitor can outcompete the substrate for the active site. Incorrect b. The active site creates a microenvironment ideal for the reaction. Incorrect c. The binding of the substrate depends on the shape of the active site. Incorrect d. The binding of the substrate changes the shape of the enzyme's active site. Correct e. Some enzymes change their structure when activators bind to the enzyme. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. collecting duct Incorrect b. loop of Henle Correct c. proximal convoluted tubule Incorrect d. glomerulus Incorrect e. Bowman's capsule Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 A localized group of organisms that belong to the same species is called a Choose one answer. a. family. Incorrect b. community. Incorrect c. ecosystem. Incorrect d. biosystem. Incorrect e. population. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses Choose one answer. a. 4, 3, 2, 1, 5 Incorrect b. 4, 3, 1, 5, 2 Incorrect c. 4, 1, 2, 3, 5 Incorrect d. 3, 4, 1, 2, 5 Incorrect e. 4, 1, 3, 2, 5 Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? Choose one answer. a. catalysis Incorrect b. anabolism Incorrect c. dehydration Incorrect d. catabolism Correct e. metabolism Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The somatic cells derived from a single-celled zygote divide by which process? Choose one answer. a. binary fission Incorrect b. mitosis Correct c. meiosis Incorrect d. cytokinesis alone Incorrect e. replication Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Where does glycolysis takes place? Choose one answer. a. mitochondrial outer membrane Incorrect b. cytosol Correct c. mitochondrial intermembrane space Incorrect d. mitochondrial inner membrane Incorrect e. mitochondrial matrix Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? Choose one answer. a. ribosomes Incorrect b. sites of energy production in cellular respiration Incorrect c. cellulose fibers in the cell wall Incorrect d. cytoskeletons Correct e. membrane proteins Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes? Choose one answer. a. 23 Incorrect b. 920 Incorrect c. 460 Incorrect d. 46 Incorrect e. About 8 million Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 One of the following people was the first to suggest that organic compounds, those found in living organisms, were distinctly different from inorganic compounds found in the nonliving world. Though this suggestion is now known to be incorrect, it stimulated important research into organic compounds. Who suggested this? Choose one answer. a. Friedrich Wohler Incorrect b. Stanley Miller Incorrect c. August Kekulé Incorrect d. Jakob Berzelius Correct e. Hermann Kolbe Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? Choose one answer. a. 5'-A-G-C-T-3' with 5'-T-C-G-A-3' Incorrect b. All of these pairs are correct. Incorrect c. 5'-G-C-G-C-3' with 5'-T-A-T-A-3' Incorrect d. 5'-A-T-G-C-3' with 5'-G-C-A-T-3' Correct e. 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Cyanide acts as a mitochondrial poison by blocking the final step in the electron transport chain. What will happen to human red blood cells if they are placed in an isotonic solution containing cyanide? Choose one answer. a. As a protective mechanism, the cells will switch to anaerobic metabolism. Incorrect b. The cells will probably be unaffected. Correct c. The cell shape will be maintained, but the mitochondria will be poisoned. Incorrect d. The cells will lyse as the cyanide concentration increases inside the cell. Incorrect e. The cells will not be able to carry oxygen. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following mechanisms for osmoregulation or nitrogen removal is correctly paired with its corresponding animal? Choose one answer. a. kidney-insect Incorrect b. metanephridium-flatworm Incorrect c. Malpighian tubule-frog Incorrect d. flame bulb-snake Incorrect e. direct cellular exchange-marine invertebrate Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Reduction of oxygen which forms water occurs during Choose one answer. a. both photosynthesis and respiration. Incorrect b. respiration. Correct c. photosynthesis. Incorrect d. neither photosynthesis nor respiration. Incorrect e. photorespiration. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water? Choose one answer. a. oxidative phosphorylation (chemiosmosis) Correct b. citric acid cycle Incorrect c. fermentation Incorrect d. glycolysis Incorrect e. oxidation of pyruvate to acetyl CoA Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 In liver cells, the inner mitochondrial membranes are about 5 X the area of the outer mitochondrial membranes, and about 17 X that of the cell's plasma membrane. What purpose must this serve? Choose one answer. a. It allows the liver cell to have fewer mitochondria. Incorrect b. It allows for increased rate of the citric acid cycle. Incorrect c. It allows for increased rate of glycolysis. Incorrect d. It increases the surface for substrate-level phosphorylation. Incorrect e. It increases the surface for oxidative phosphoryation. Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Muscle cells, when an individual is exercising heavily and when the muscle becomes oxygen deprived, convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells? Choose one answer. a. It produces CO2 and water. Incorrect b. It reduces FADH2 to FAD+. Incorrect c. It is converted to alcohol. Incorrect d. It is taken to the liver and converted back to pyruvate. Correct e. It is converted to NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 In mechanism, photophosphorylation is most similar to Choose one answer. a. substrate-level phosphorylation in glycolysis. Incorrect b. oxidative phosphorylation in cellular respiration. Correct c. reduction of NADP+. Incorrect d. the Calvin cycle. Incorrect e. carbon fixation. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound? Choose one answer. a. It should dissolve in a nonpolar solvent. Incorrect b. It lacks an asymmetric carbon, and it is probably a fat or lipid. Incorrect c. It won't form hydrogen bonds with water. Incorrect d. It should dissolve in water. Correct e. It is hydrophobic. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? Choose one answer. a. starches Incorrect b. lipids Incorrect c. glucose Incorrect d. proteins Correct e. steroids Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. ATP and NADPH Correct b. ADP and NADP Incorrect c. P700 and P680 Incorrect d. heat and fluorescence Incorrect e. ATP and P700 Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the following takes place as an ice cube cools a drink? Choose one answer. a. Kinetic energy in the drink decreases. Correct b. Evaporation of the water in the drink increases. Incorrect c. A calorie of heat energy is transferred from the ice to the water of the drink. Incorrect d. The specific heat of the water in the drink decreases. Incorrect e. Molecular collisions in the drink increase. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following pairs of structures is least likely to represent homology? Choose one answer. a. The mitochondria of a plant and those of an animal Incorrect b. The hemoglobin of a baboon and that of a gorilla Incorrect c. The wings of a bat and the arms of a human Incorrect d. The brain of a cat and that of a dog Incorrect e. The wings of a bird and those of an insect Correct Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long? Choose one answer. a. 8 Incorrect b. 12 Incorrect c. 9 Incorrect d. 10 Correct e. 11 Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual? Choose one answer. a. 47, XXX Incorrect b. 45, X Incorrect c. 47, XXY Incorrect d. 47, XYY Incorrect e. 47, +21 Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Two characters that appear in a 9:3:3:1 ratio in the F2 generation should have which of the following properties? Choose one answer. a. Each of the genes controlling the characters has two alleles. Incorrect b. Sixteen different phenotypes are possible. Incorrect c. Four genes are involved. Incorrect d. The genes controlling the characters obey the law of independent assortment. Correct e. Each of the traits is controlled by single genes. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Archaea, kingdom Bacteria Incorrect b. domain Eukarya, kingdom Fungi Correct c. domain Eukarya, kingdom Protista Incorrect d. domain Eukarya, kingdom Plantae Incorrect e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. a. they cannot be manufactured by the organism. Correct b. they are subunits of important polymers. Incorrect c. only those animals use the nutrients. Incorrect d. only some foods contain them. Incorrect e. they are necessary coenzymes. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 16 Started on Saturday, January 17, 2009, 10:33 AM Completed on Saturday, January 17, 2009, 10:33 AM Time taken 9 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Most cells cannot harness heat to perform work because Choose one answer. a. cells do not have much heat; they are relatively cool. Incorrect b. heat denatures enzymes. Incorrect c. heat is not a form of energy. Incorrect d. heat can never be used to do work. Incorrect e. temperature is usually uniform throughout a cell. Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Whenever energy is transformed, there is always an increase in the Choose one answer. a. free energy of the universe. Incorrect b. enthalpy of the universe. Incorrect c. entropy of the system. Incorrect d. entropy of the universe. Correct e. free energy of the system. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which process is most directly driven by light energy? Choose one answer. a. creation of a pH gradient by pumping protons across the thylakoid membrane Incorrect b. reduction of NADP+ molecules Incorrect c. ATP synthesis Incorrect d. carbon fixation in the stroma Incorrect e. removal of electrons from chlorophyll molecules Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of these should decline in hybrid zones where reinforcement is occurring? Choose one answer. a. hybrid sterility Incorrect b. the genetic distinctness of two gene pools Incorrect c. mutation rate Incorrect d. gene flow between distinct gene pools Correct e. speciation Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 What is the purpose of beta oxidation in respiration? Choose one answer. a. breakdown of fatty acids Correct b. control of ATP accumulation Incorrect c. feedback regulation Incorrect d. oxidation of glucose Incorrect e. oxidation of pyruvate Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 After ingestion, the first type of macromolecule to be worked on by enzymes in the human digestive system is Choose one answer. a. cholesterol Incorrect b. carbohydrate. Correct c. protein. Incorrect d. nucleic acid. Incorrect e. glucose. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). Thus, H2CO3 ? HCO3- + H+ If the pH of the blood drops, one would expect Choose one answer. a. the concentration of hydroxide ion (OH-) to increase. Incorrect b. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. Incorrect c. the HCO3- to act as a base and remove excess H+ with the formation of H2CO3. Correct d. the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3. Incorrect e. the concentration of bicarbonate ion (HCO3-) to increase. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be Choose one answer. a. 2x. Correct b. 0.5x. Incorrect c. 0.25x. Incorrect d. 4x. Incorrect e. x. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following is reflective of the phrase "the whole is greater than the sum of its parts"? Choose one answer. a. feedback regulations Incorrect b. reductionism Incorrect c. emergent properties Correct d. high-throughput technology Incorrect e. natural selection Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? Choose one answer. a. water's high surface tension Incorrect b. water's ability to dissolve molecules in the air Incorrect c. the release of heat by the formation of hydrogen bonds Incorrect d. the absorption of heat by the breaking of hydrogen bonds Correct e. water's change in density when it condenses Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. H2O and NADPH. Incorrect b. sugar and O2. Incorrect c. light energy. Incorrect d. ATP and NADPH. Correct e. CO2 and ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which group is composed entirely of individuals who maintained that species are fixed (i.e., unchanging)? Choose one answer. a. Aristotle, Linnaeus, and Cuvier Correct b. Linnaeus, Cuvier, and Lamarck Incorrect c. Hutton, Lyell, and Darwin Incorrect d. Lyell, Linnaeus, and Lamarck Incorrect e. Aristotle, Cuvier, and Lamarck Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. a. concentrate photons within the stroma Incorrect b. synthesize ATP from ADP and Pi Incorrect c. harvest photons and transfer light energy to the reaction-center chlorophyll Correct d. split water and release oxygen to the reaction-center chlorophyll Incorrect e. transfer electrons to ferredoxin and then NADPH Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Eukarya, kingdom Plantae Incorrect b. domain Archaea, kingdom Bacteria Incorrect c. domain Eukarya, kingdom Protista Incorrect d. domain Bacteria, kingdom Prokaryota Incorrect e. domain Eukarya, kingdom Fungi Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Males are more often affected by sex-linked traits than females because Choose one answer. a. mutations on the Y chromosome often worsen the effects of X-linked mutations. Incorrect b. female hormones such as estrogen often compensate for the effects of mutations on the X. Incorrect c. males are hemizygous for the X chromosome. Correct d. male hormones such as testosterone often alter the effects of mutations on the X chromosome. Incorrect e. X chromosomes in males generally have more mutations than X chromosomes in females. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. green and yellow Incorrect b. green, blue, and yellow Incorrect c. blue, green, and red Incorrect d. red and yellow Incorrect e. blue and violet Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Synthesis of ATP by the chemiosmotic mechanism occurs during Choose one answer. a. photosynthesis. Incorrect b. neither photosynthesis nor respiration. Incorrect c. both photosynthesis and respiration. Correct d. photorespiration. Incorrect e. respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Intracellular digestion of peptides is usually immediately preceded by which process? Choose one answer. a. absorption Incorrect b. secretion Incorrect c. elimination Incorrect d. hydrolysis Incorrect e. endocytosis Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids? Choose one answer. a. ribosome Incorrect b. mitochondrion Incorrect c. smooth endoplasmic reticulum Correct d. lysosome Incorrect e. contractile vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 For living organisms, which of the following is an important consequence of the first law of thermodynamics? Choose one answer. a. The organism ultimately must obtain all of the necessary energy for life from its environment. Correct b. The entropy of an organism decreases with time as the organism grows in complexity. Incorrect c. Organisms are unable to transform energy. Incorrect d. The energy content of an organism is constant. Incorrect e. Life does not obey the first law of thermodynamics. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which of the following animals is incorrectly paired with its feeding mechanism? Choose one answer. a. snakebulk feeder Incorrect b. lionsubstrate feeder Correct c. clamsuspension feeder Incorrect d. baleen whalesuspension feeder Incorrect e. aphidfluid feeder Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 The frequency of heterozygosity for the sickle cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? Choose one answer. a. The malarial parasite changing the allele Incorrect b. Mendel's law of segregation Incorrect c. Darwin's observations of competition Incorrect d. Mendel's law of independent assortment Incorrect e. Darwin's explanation of natural selection Correct Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following minerals is associated with its use in animals? Choose one answer. a. sulfuringredient of nucleic acids Incorrect b. ironnecessary for thyroid function Incorrect c. magnesiumcofactor in enzymes that make ATP Incorrect d. iodineimportant in nerve function Incorrect e. calciumconstruction and maintenance of bone Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 People with sickle-cell trait Choose one answer. a. are heterozygous for the sickle-cell allele. Incorrect b. have increased resistance to malaria. Incorrect c. are usually healthy. Incorrect d. All of the above Correct e. produce normal and abnormal hemoglobin. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following solutions has the greatest concentration of hydrogen ions [H+]? Choose one answer. a. gastric juice at pH 2 Correct b. black coffee at pH 5 Incorrect c. tomato juice at pH 4 Incorrect d. vinegar at pH 3 Incorrect e. household bleach at pH 12 Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect b. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect c. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct d. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect e. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. secretion Incorrect b. active transport Incorrect c. ultrafiltration Incorrect d. filtration Incorrect e. selective reabsorption Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 A cell divides to produce two daughter cells that are genetically different. Choose one answer. a. The statement is true for mitosis and meiosis II. Incorrect b. The statement is true for meiosis I only. Correct c. The statement is true for mitosis and meiosis I. Incorrect d. The statement is true for mitosis only. Incorrect e. The statement is true for meiosis II only. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following is considered an open system? Choose one answer. a. liquid in a corked bottle Incorrect b. a sealed terrarium Incorrect c. an organism Correct d. food cooking in a pressure cooker Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 At an atmospheric pressure of 870 mm Hg, what is the contribution of oxygen? Choose one answer. a. 100 mm Hg Incorrect b. 127 mm Hg Incorrect c. 151 mm Hg Incorrect d. 219 mm Hg Incorrect e. 182 mm Hg Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. primary cell wall ? plasma membrane ? cytoplasm ? tonoplast Correct b. plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect c. secondary cell wall ? plasma membrane ? primary cell wall ? cytoplasm ? tonoplast Incorrect d. primary cell wall ? plasma membrane ? tonoplast ? cytoplasm ? vacuole Incorrect e. tonoplast ? primary cell wall ? plasma membrane ? cytoplasm Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Sexual dimorphism is most often a result of Choose one answer. a. artificial selection. Incorrect b. pansexual selection. Incorrect c. intrasexual selection. Incorrect d. stabilizing selection. Incorrect e. intersexual selection. Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect b. a system of individualized exchange tubules for each cell group Incorrect c. direct exchange of nutrients with the surrounding medium Incorrect d. a system to circulate gases, nutrients, and wastes to and from cells Correct e. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? Choose one answer. a. beer the most, salt solution the least Correct b. water the most, beer the least Incorrect c. There will be no significant difference between these groups. Incorrect d. salt solution the most, water the least Incorrect e. beer the most, water the least Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 DNA is replicated at this time of the cell cycle: Choose one answer. a. S Correct b. G2 Incorrect c. G1 Incorrect d. M Incorrect e. G0 Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 When pairs of homologous chromosomes separate during anaphase I, Choose one answer. a. the sister chromatids remain attached to one another. Correct b. the synaptonemal complex is visible under the light microscope. Incorrect c. the maternal chromosomes all move to the same daughter cell. Incorrect d. recombination is not yet complete. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. oxidation of pyruvate to acetyl CoA Incorrect b. citric acid cycle Incorrect c. oxidative phosphorylation Incorrect d. fermentation and chemiosmosis Incorrect e. glycolysis and fermentation Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Charles Darwin proposed a mechanism for descent with modification which stated that organisms of a particular species are adapted to their environment when they possess Choose one answer. a. non-inheritable traits that enhance their survival and reproductive success in the local environment. Incorrect b. non-inheritable traits that enhance their survival in the local environment. Incorrect c. non-inheritable traits that enhance their reproductive success in the local environment. Incorrect d. inheritable traits that decrease their survival and reproductive success in the local environment. Incorrect e. inheritable traits that enhance their survival and reproductive success in the local environment. Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? Choose one answer. a. 4:3 male to female Incorrect b. 1:2 male to female Incorrect c. 2:1 male to female Correct d. 1:1 male to female Incorrect e. 3:1 male to female Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. interaction with the environment Incorrect b. emergent properties Incorrect c. reductionism Correct d. structure and function Incorrect e. evolution Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following is/are a cause(s) of vasoconstriction? Choose one answer. a. lying down after standing Incorrect b. increased blood pressure Incorrect c. standing after lying down Incorrect d. stress or hormone concentration Correct e. histamine secretion Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? Choose one answer. a. 100 mL of pure water Incorrect b. 100 mL of household cleanser containing 0.5M ammonia Correct c. 100 mL of tomato juice Incorrect d. 100 mL of freshly-squeezed orange juice Incorrect e. 100 mL of freshly-brewed coffee Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following nitrogenous wastes requires hardly any water for its excretion? Choose one answer. a. amino acid Incorrect b. nitrogen gas Incorrect c. urea Incorrect d. uric acid Correct e. ammonia Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? Choose one answer. a. microvilli, alveoli, and glomeruli Incorrect b. egg cells (ova), uterus, and kidneys Incorrect c. sperm, larynx, and trachea Correct d. all ducts, such as those from salivary or sebaceous glands Incorrect e. limbs, hearts, areas with a good deal of contraction Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Amino acids are acids because they always possess which functional group? Choose one answer. a. amino Incorrect b. sulfhydryl Incorrect c. carbonyl Incorrect d. carboxyl Correct e. aldehyde Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following is true of ammonia? Choose one answer. a. It is soluble in water. Correct b. It can be stored as a precipitate. Incorrect c. It is the major nitrogenous waste excreted by insects. Incorrect d. It has low toxicity relative to urea. Incorrect e. It is metabolically more expensive to synthesize than urea. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Grana, thylakoids, and stroma are all components found in Choose one answer. a. nuclei. Incorrect b. lysosomes. Incorrect c. mitochondria. Incorrect d. vacuoles. Incorrect e. chloroplasts. Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to Choose one answer. a. cause iron in ocean water and terrestrial rocks to rust (oxidize). Correct b. make it easier to maintain reduced molecules. Incorrect c. prevent the formation of an ozone layer. Incorrect d. make life on land difficult for aerobic organisms. Incorrect e. change the atmosphere from oxidizing to reducing. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which of the following is a statement of the first law of thermodynamics? Choose one answer. a. Energy cannot be transferred or transformed. Incorrect b. The entropy of the universe is constant. Incorrect c. Energy cannot be created or destroyed. Correct d. Kinetic energy is stored energy that results from the specific arrangement of matter. Incorrect e. The entropy of the universe is decreasing. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Energy released by the electron transport chain is used to pump H+ ions into which location? Choose one answer. a. cytosol Incorrect b. mitochondrial intermembrane space Correct c. mitochondrial matrix Incorrect d. mitochondrial outer membrane Incorrect e. mitochondrial inner membrane Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? Choose one answer. a. 80 mm Hg Correct b. 760 mm Hg Incorrect c. 380 mm Hg Incorrect d. 160 mm Hg Incorrect e. 0 mm Hg Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely to occur in prokaryotic respiration? Choose one answer. a. in the cytoplasm Incorrect b. on the inner mitochondrial membrane Incorrect c. on the endoplasmic reticulum Incorrect d. on the inner nuclear envelope Incorrect e. on the inner plasma membrane Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. results from active transport. Incorrect b. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct c. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect d. is very selective as to which subprotein sized molecules are transferred. Incorrect e. transfers large molecules as easily as small ones. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Density-dependent inhibition is explained by which of the following? Choose one answer. a. As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. Incorrect b. As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. Correct c. As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. Incorrect d. As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. Incorrect e. As cells become more numerous, more and more of them enter the S phase of the cell cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes? Choose one answer. a. 50% Incorrect b. 0% Incorrect c. 100% Correct d. 75% Incorrect e. 25% Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Systems biology is mainly an attempt to Choose one answer. a. build high-throughput machines for the rapid acquisition of biological data. Incorrect b. construct models of the behavior of entire biological systems. Correct c. simplify complex problems by reducing the system into smaller, less complex units. Incorrect d. speed up the technological application of scientific knowledge. Incorrect e. understand the integration of all levels of biological organization from molecules to the biosphere. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations? Choose one answer. a. Natural selection Correct b. Mutation Incorrect c. Non-random mating Incorrect d. Gene flow Incorrect e. Genetic drift Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Where does glycolysis takes place? Choose one answer. a. mitochondrial inner membrane Incorrect b. cytosol Correct c. mitochondrial intermembrane space Incorrect d. mitochondrial outer membrane Incorrect e. mitochondrial matrix Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. oxygen. Correct b. water. Incorrect c. ADP. Incorrect d. NAD+. Incorrect e. pyruvate. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. must be ingested in the diet. Incorrect b. is not found in many proteins. Incorrect c. can be made by the animal's body from other substances. Correct d. is not used by the animal in biosynthesis. Incorrect e. is less important than an essential amino acid. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 17 Started on Saturday, January 17, 2009, 10:34 AM Completed on Saturday, January 17, 2009, 10:34 AM Time taken 11 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 After ingestion, the first type of macromolecule to be worked on by enzymes in the human digestive system is Choose one answer. a. cholesterol Incorrect b. protein. Incorrect c. carbohydrate. Correct d. nucleic acid. Incorrect e. glucose. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Chromatids are separated from each other. Choose one answer. a. The statement is true for mitosis and meiosis II. Correct b. The statement is true for meiosis I only. Incorrect c. The statement is true for mitosis only. Incorrect d. The statement is true for meiosis II only. Incorrect e. The statement is true for mitosis and meiosis I. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which event is nearest in time to the end of the period known as snowball Earth? Choose one answer. a. oxygenation of Earth's seas and atmosphere Incorrect b. Permian extinction Incorrect c. evolution of true multicellularity Incorrect d. evolution of mitochondria Incorrect e. Cambrian explosion Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic of all of these extracellular structures? Choose one answer. a. They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. Incorrect b. They are constructed of materials that are largely synthesized in the cytoplasm and then transported out of the cell. Correct c. They are composed of a mixture of lipids and carbohydrates. Incorrect d. They must block water and small molecules in order to regulate the exchange of matter and energy with their environment. Incorrect e. They must permit information transfer between the cell's cytoplasm and the nucleus. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals? Choose one answer. a. Hemocyanin carries appreciably more carbon dioxide. Incorrect b. The oxygen dissociation curve for hemocyanin is linear. Incorrect c. The protein of hemocyanin is not bound to metal. Incorrect d. Hemocyanin has protein coupled to copper rather than iron. Correct e. Hemocyanin includes cyanic acid. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following takes place as an ice cube cools a drink? Choose one answer. a. Molecular collisions in the drink increase. Incorrect b. A calorie of heat energy is transferred from the ice to the water of the drink. Incorrect c. Evaporation of the water in the drink increases. Incorrect d. The specific heat of the water in the drink decreases. Incorrect e. Kinetic energy in the drink decreases. Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Cell membranes are asymmetrical. Which of the following is a most likely explanation? Choose one answer. a. Cell membranes communicate signals from one organism to another. Incorrect b. The "innerness" and "outerness" of membrane surfaces are predetermined by genes. Incorrect c. Proteins can only span cell membranes if they are hydrophobic. Incorrect d. Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. Correct e. The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of the following couples chemiosmosis to energy storage? Choose one answer. a. ATP synthase Correct b. electron transport Incorrect c. cytochromes Incorrect d. FADH2 Incorrect e. NADH Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following does not occur during the Calvin cycle? Choose one answer. a. regeneration of the CO2 acceptor Incorrect b. consumption of ATP Incorrect c. release of oxygen Correct d. oxidation of NADPH Incorrect e. carbon fixation Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis? Choose one answer. a. Half of the gametes will be n + 1, and half will be n — 1. Incorrect b. 1/4 of the gametes will be n + 1, one will be n — 1, and two will be n. Correct c. All the gametes will be diploid. Incorrect d. There will be three extra gametes. Incorrect e. Two of the four gametes will be haploid, and two will be diploid. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is not a theme that unifies biology? Choose one answer. a. structure and function Incorrect b. evolution Incorrect c. reductionism Correct d. interaction with the environment Incorrect e. emergent properties Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? Choose one answer. a. water's ability to dissolve molecules in the air Incorrect b. water's change in density when it condenses Incorrect c. the absorption of heat by the breaking of hydrogen bonds Correct d. water's high surface tension Incorrect e. the release of heat by the formation of hydrogen bonds Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following statements is true concerning catabolic pathways? Choose one answer. a. They are endergonic. Incorrect b. They build up complex molecules such as protein from simpler compounds. Incorrect c. They combine molecules into more energy-rich molecules. Incorrect d. They are spontaneous and do not need enzyme catalysis. Incorrect e. They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which one of the following, if present in a urine sample, would likely be caused by trauma? Choose one answer. a. erythrocytes Correct b. glucose Incorrect c. amino acids Incorrect d. vitamins Incorrect e. salts Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 In order for a protein to be an integral membrane protein it would have to be which of the following? Choose one answer. a. amphipathic Correct b. exposed on only one surface of the membrane Incorrect c. hydrophilic Incorrect d. completely covered with phospholipids Incorrect e. hydrophobic Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It may explain the transmission of Duchenne muscular dystrophy. Incorrect b. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect c. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct d. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? Choose one answer. a. by decreasing the activation energy of the reaction Incorrect b. by changing the shape of a reactant Correct c. by acting as a coenzyme for the reaction Incorrect d. by binding at the active site of the enzyme Incorrect e. by changing the free energy change of the reaction Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following statements best summarizes evolution as it is viewed today? Choose one answer. a. It is the descent of humans from the present-day great apes. Incorrect b. It is goal-directed. Incorrect c. It is synonymous with the process of gene flow. Incorrect d. It is the differential survival and reproduction of the most-fit phenotypes. Correct e. It represents the result of selection for acquired characteristics. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? Choose one answer. a. Breed this plant with another plant with much weaker traits. Incorrect b. Force the plant to self-pollinate to obtain an identical one. Incorrect c. Backtrack through her previous experiments to obtain another plant with the same traits. Incorrect d. Add nitrogen to the soil of the offspring of this plant so the desired traits continue. Incorrect e. Clone the plant asexually to produce an identical one. Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 A pedigree analysis for a given disorder's occurrence in a family shows that, although both parents of an affected child are normal, each of the parents has had affected relatives with the same condition. The disorder is then which of the following? Choose one answer. a. Dominant Incorrect b. A new mutation Incorrect c. Incompletely dominant Incorrect d. Maternally inherited Incorrect e. Recessive Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Individuals whose diet consists primarily of corn would likely become Choose one answer. a. anorexic. Incorrect b. malnourished. Correct c. overnourished. Incorrect d. undernourished. Incorrect e. obese. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Inside an active mitochondrion, most electrons follow which pathway? Choose one answer. a. electron transport chain ? citric acid cycle ? ATP ? oxygen Incorrect b. citric acid cycle ? FADH2? electron transport chain ? ATP Incorrect c. citric acid cycle ? NADH ? electron transport chain ? oxygen Correct d. pyruvate ? citric acid cycle ? ATP ? NADH ? oxygen Incorrect e. glycolysis ? NADH ? oxidative phosphorylation ? ATP ? oxygen Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 How do ADH and RAAS work together in maintaining osmoregulatory homeostasis? Choose one answer. a. ADH an RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS removal of water when it is in excess in body fluids. Incorrect b. ADH monitors appropriate osmolarity by reabsorption of water, and RAAS maintains osmolarity by stimulating Na+ reabsorption. Correct c. Both stimulate the adrenal gland to secrete aldosterone which increases both blood volume and pressure. Incorrect d. Only when they are together in the receptor sites of proximal tubule cells, will reabsorption of essential nutrients back into the blood take place. Incorrect e. ADH monitors osmolarity of the blood and RAAS regulates blood volume. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have which of the following? Choose one answer. a. a closed circulatory system Correct b. an open circulatory system Incorrect c. hemolymph Incorrect d. a gastrovascular cavity Incorrect e. branched tracheae Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10-12M? Choose one answer. a. pH 10 Incorrect b. pH 12 Incorrect c. pH 2 Correct d. pH 14 Incorrect e. pH 4 Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following best describes the logic of hypothesis-based science? Choose one answer. a. If my observations are accurate, they will support my hypothesis. Incorrect b. If my prediction is correct, it will lead to a testable hypothesis. Incorrect c. If my experiments are set up right, they will lead to a testable hypothesis. Incorrect d. If my hypothesis is correct, I can expect certain test results. Correct e. If I generate a testable hypothesis, tests and observations will support it. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Recent evidence points to the conclusion that the ancestral finches of the Galapagos originated in the islands of the Caribbean. Answer: True False Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. donate electrons Incorrect b. act as reducing agents Incorrect c. both oxidize and reduce during electron transport Correct d. act as oxidizing agents Incorrect e. transport protons within the mitochondria and chloroplasts Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the Choose one answer. a. lack of genetic variation among all members of a population. Incorrect b. ability of populations to undergo modification as they adapt to a particular environment. Correct c. tendency of organisms to produce the exact number of offspring that the environment can support. Incorrect d. relative stability of a well-adapted population's numbers over many generations. Incorrect e. unlimited resources that support population growth in most natural environments. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 The mathematical expression for the change in free energy of a system is G =H-TS. Which of the following is (are) correct? Choose one answer. a. H is the change in entropy, the energy available to do work. Incorrect b. S is the change in enthalpy, a measure of randomness. Incorrect c. T is the temperature in degrees Celsius. Incorrect d. G is the change in free energy. Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Some bacteria are metabolically active in hot springs because Choose one answer. a. they are able to maintain a cooler internal temperature. Incorrect b. they use molecules other than proteins or RNAs as their main catalysts. Incorrect c. their enzymes are completely insensitive to temperature. Incorrect d. their enzymes have high optimal temperatures. Correct e. high temperatures make catalysis unnecessary. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 The frequency of heterozygosity for the sickle cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? Choose one answer. a. Mendel's law of segregation Incorrect b. The malarial parasite changing the allele Incorrect c. Mendel's law of independent assortment Incorrect d. Darwin's observations of competition Incorrect e. Darwin's explanation of natural selection Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs? Choose one answer. a. Water is less dense than air. Incorrect b. Water contains much less O2 than air per unit volume. Correct c. Gills have less surface area than lungs. Incorrect d. Gills allow only unidirectional transport Incorrect e. Gills allow water to flow in one direction Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following are adaptations to a carnivorous diet? Choose one answer. a. a rumen Incorrect b. ingestion of feces Incorrect c. broad, flat molars Incorrect d. amylase Incorrect e. bile salts Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 The molecular mass of glucose (C6H12O6) is 180 g. Which of the following procedures should you carry out to make a 0.5 M solution of glucose? Choose one answer. a. Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L. Correct b. Dissolve 0.5 g of glucose in 1 L of water. Incorrect c. Dissolve 180 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L. Incorrect d. Dissolve 180 g of glucose in 1 L of water. Incorrect e. Dissolve 0.5 g of glucose in a small volume of water, and then add more water until the total volume of solution is 1 L. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Unlike an earthworm's metanephridia, a mammalian nephron Choose one answer. a. receives filtrate from blood instead of coelomic fluid. Correct b. functions in both osmoregulation and excretion. Incorrect c. forms urine by changing fluid composition inside a tubule. Incorrect d. has a transport epithelium. Incorrect e. is intimately associated with a capillary network. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? Choose one answer. a. Urea makes lungfish tissue hypoosmotic to the pool. Incorrect b. Urea takes less energy to synthesize than ammonia. Incorrect c. The highly toxic urea makes the pool uninhabitable to potential competitors. Incorrect d. Small stagnant pools do not provide enough water to dilute the toxic ammonia. Correct e. Urea forms an insoluble precipitate. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. a. concentrate photons within the stroma Incorrect b. harvest photons and transfer light energy to the reaction-center chlorophyll Correct c. synthesize ATP from ADP and Pi Incorrect d. transfer electrons to ferredoxin and then NADPH Incorrect e. split water and release oxygen to the reaction-center chlorophyll Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. Choose one answer. a. NaCl crystals will dissolve readily in methanol but will not dissolve in water. Incorrect b. NaCl crystals will NOT dissolve in either water or methanol. Incorrect c. Equal amounts of NaCl crystals will dissolve in both water and methanol. Incorrect d. When the first crystals of NaCl are added to water or to methanol, they will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster. Incorrect e. NaCl crystals will dissolve readily in water but will not dissolve in methanol. Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. There is no relationship between the light reactions and the Calvin cycle. Incorrect b. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect c. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct d. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect e. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Systems biology is mainly an attempt to Choose one answer. a. understand the integration of all levels of biological organization from molecules to the biosphere. Incorrect b. speed up the technological application of scientific knowledge. Incorrect c. simplify complex problems by reducing the system into smaller, less complex units. Incorrect d. construct models of the behavior of entire biological systems. Correct e. build high-throughput machines for the rapid acquisition of biological data. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 In mitochondria, exergonic redox reactions Choose one answer. a. reduce carbon atoms to carbon dioxide. Incorrect b. are directly coupled to substrate-level phosphorylation. Incorrect c. provide the energy that establishes the proton gradient. Correct d. are coupled via phosphorylated intermediates to endergonic processes. Incorrect e. are the source of energy driving prokaryotic ATP synthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? Choose one answer. a. interphase Incorrect b. prophase Incorrect c. metaphase Correct d. anaphase Incorrect e. telophase Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Bacteria are beneficial to animal nutrition, including that of humans. Which of the following is among their greatest benefits to us? Choose one answer. a. production of vitamins A and C Incorrect b. absorption of organic materials Incorrect c. recovery of water from fecal matter Incorrect d. production of biotin and vitamin K Correct e. generation of gases needed for elimination Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Among enzymes, kinases catalyze phosphorylation, while phosphatases catalyze removal of phosphate(s). A cell's use of these enzymes can therefore function as an on-off switch for various processes. Which of the following is probably involved? Choose one answer. a. a change in the optimal pH at which a reaction will occur Incorrect b. the change in a protein's charge leading to cleavage Incorrect c. a change in the optimal temperature at which a reaction will occur Incorrect d. the change in a protein's charge leading to a conformational change Correct e. the excision of one or more peptides Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 In modern terminology, diversity is understood to be a result of genetic variation. Sources of variation for evolution include all of the following except Choose one answer. a. recombination at fertilization. Incorrect b. mistakes in translation of structural genes. Correct c. recombination by crossing over in meiosis. Incorrect d. translocations and mistakes in meiosis. Incorrect e. mistakes in DNA replication. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 What is the source of the extra chromosome 21 in an individual with Down syndrome? Choose one answer. a. Nondisjunction in the father only Incorrect b. Duplication of the chromosome Incorrect c. It is impossible to detect with current technology Incorrect d. Nondisjunction or translocation in either parent Correct e. Nondisjunction in the mother only Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. That the actual forelimbs of these mammals do not seem to be optimally arranged is because Choose one answer. a. natural selection operates in ways that are beyond the capability of the human mind to comprehend. Incorrect b. in many cases, phenotype is not merely determined by genotype, but by the environment as well. Incorrect c. natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time. Incorrect d. natural selection is generally limited to modifying structures that were present in previous generations and in previous species. Correct e. though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 The somatic cells derived from a single-celled zygote divide by which process? Choose one answer. a. cytokinesis alone Incorrect b. mitosis Correct c. meiosis Incorrect d. replication Incorrect e. binary fission Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Blood glucagon increases. Correct b. Blood insulin increases. Incorrect c. Both insulin and glucagon decrease. Incorrect d. Thyroid hormone is increased. Incorrect e. Both insulin and glucagon increase. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely true? Choose one answer. a. Glucose is entering the cell along its concentration gradient. Incorrect b. The sodium ions are moving down their electrochemical gradient while glucose is moving up. Incorrect c. Potassium ions move across the same gradient as sodium ions. Incorrect d. A substance that blocked sodium ions from binding to the cotransport protein would also block the transport of glucose. Correct e. Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. light energy. Incorrect b. sugar and O2. Incorrect c. H2O and NADPH. Incorrect d. ATP and NADPH. Correct e. CO2 and ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Breathing is usually regulated by Choose one answer. a. the lungs and the larynx. Incorrect b. hemoglobin levels in the blood. Incorrect c. CO2 and O2 concentration and pH-level sensors. Correct d. erythropoietin levels in the blood. Incorrect e. the concentration of red blood cells. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to Choose one answer. a. inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate. Incorrect b. activate the enzyme and increase the rates of glycolysis and the citric acid cycle. Incorrect c. activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Incorrect d. inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Correct e. inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart? Choose one answer. a. reptiles Incorrect b. fishes Correct c. mammals Incorrect d. birds Incorrect e. amphibians Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? Choose one answer. a. energy released as electrons flow through the electron transport system Incorrect b. energy released from movement of protons through ATP synthase Correct c. No external source of energy is required because the reaction is exergonic. Incorrect d. energy released from substrate-level phosphorylation Incorrect e. energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. podocytes Incorrect b. juxtamedullary nephrons Correct c. ureter Incorrect d. Bowman's capsule Incorrect e. urethra Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions? Choose one answer. a. Maintenance of connective tissue shape requires cells to adhere to one another. Incorrect b. The relative shapelessness of animal cells requires a mechanism for keeping the cells aligned. Incorrect c. Large molecules, especially proteins, do not readily get through one, much less two adjacent cell membranes. Correct d. Cell-to-cell communication requires physical attachment of one cell to another. Incorrect e. Cell membranes do not distinguish the types of ions and molecules passing through them. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The plant's height is 25 centimeters (cm). Incorrect b. The six pairs of robins hatched an average of three chicks. Incorrect c. The temperature decreased from 20°C to 15°C. Incorrect d. The fish swam in a zig-zag motion. Correct e. The contents of the stomach are mixed every 20 seconds. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following are primarily responsible for cytokinesis in plant cells? Choose one answer. a. centrioles and basal bodies Incorrect b. cyclin-dependent kinases Incorrect c. actin and myosin Incorrect d. Golgi-derived vesicles Correct e. kinetochores Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 18 Started on Saturday, January 17, 2009, 10:34 AM Completed on Saturday, January 17, 2009, 10:35 AM Time taken 9 secs Raw score 1/60 (2%) Grade out of a maximum of Question 1 Marks: 1 Which of the following span the phospholipids bilayer, usually a number of times? Choose one answer. a. transmembrane proteins Correct b. glycoproteins Incorrect c. peripheral proteins Incorrect d. integrins Incorrect e. integral proteins Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans, or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example? Choose one answer. a. ecological Incorrect b. biological Correct c. morphological Incorrect d. phylogenetic Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes increase the rate of a reaction. Correct b. Enzymes decrease the free energy change of a reaction. Incorrect c. Enzymes prevent changes in substrate concentrations. Incorrect d. Enzymes are permanently altered by the reactions they catalyze. Incorrect e. Enzymes change the direction of chemical reactions. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. enzymatic catalysis. Incorrect b. feedback inhibition. Incorrect c. positive feedback. Correct d. negative feedback. Incorrect e. a bioinformatic system. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. Those cells would have __________ picograms at the end of the S phase and __________ picograms at the end of G2. Choose one answer. a. 12; 16 Incorrect b. 16; 8 Incorrect c. 8; 8 Incorrect d. 16; 16 Correct e. 8; 16 Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which describes the ABO blood group system? Choose one answer. a. Epistasis Incorrect b. Pleiotropy Incorrect c. Multiple alleles Correct d. Incomplete dominance Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. Choose one answer. a. Equal amounts of NaCl crystals will dissolve in both water and methanol. Incorrect b. NaCl crystals will dissolve readily in water but will not dissolve in methanol. Correct c. NaCl crystals will dissolve readily in methanol but will not dissolve in water. Incorrect d. NaCl crystals will NOT dissolve in either water or methanol. Incorrect e. When the first crystals of NaCl are added to water or to methanol, they will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 How is photosynthesis similar in C4 and CAM plants? Choose one answer. a. In both cases, thylakoids are not involved in photosynthesis. Incorrect b. In both cases, rubisco is not used to fix carbon initially. Correct c. Both types of plants make sugar without the Calvin cycle. Incorrect d. Both types of plants make most of their sugar in the dark. Incorrect e. In both cases, only photosystem I is used. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways? Choose one answer. a. feedback regulation Incorrect b. entropy Incorrect c. bioenergetics Incorrect d. energy coupling Correct e. cooperativity Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? Choose one answer. a. The number of phosphates is three instead of two. Incorrect b. The nitrogen-containing base is different. Incorrect c. The number of phosphates is three instead of one. Incorrect d. The sugar molecule is different. Incorrect e. There is no difference. Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 The main source of energy for producers in an ecosystem is Choose one answer. a. light energy. Correct b. thermal energy. Incorrect c. kinetic energy. Incorrect d. chemical energy. Incorrect e. ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Collecting data based on observation is an example of __________; analyzing this data to reach a conclusion is an example of __________ reasoning. Choose one answer. a. hypothesis-based science; deductive Incorrect b. discovery science; inductive Correct c. hypothesis-based science; inductive Incorrect d. the process of science; deductive Incorrect e. descriptive science; deductive Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 What is unique about transport epithelial cells in the ascending loop of Henle in humans? Choose one answer. a. They are not affected by high levels of nitrogenous wastes. Incorrect b. 50% of their cell mass is comprised of smooth endoplasmic reticulum. Incorrect c. They are the largest epithelial cells in the body. Incorrect d. They are not in contact with interstitial fluid. Incorrect e. Their membranes are impermeable to water. Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following factors would tend to increase membrane fluidity? Choose one answer. a. a lower temperature Incorrect b. a greater proportion of saturated phospholipids Incorrect c. a greater proportion of unsaturated phospholipids Correct d. a relatively high protein content in the membrane Incorrect e. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 All of the following are polysaccharides except Choose one answer. a. starch Incorrect b. chitin Incorrect c. glycogen Correct d. cellulose Incorrect e. amylopectin Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a shark inhabiting freshwater Lake Nicaragua Incorrect b. a marine shark Incorrect c. a salmon in freshwater Incorrect d. a marine bony fish Correct e. a freshwater bony fish Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. a. 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 Incorrect b. 38 ATP, 6 CO2, 3 NADH, and 12 FADH2 Incorrect c. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct d. 2 ATP, 2 CO2, 1 NADH, and 3 FADH2 Incorrect e. 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which one of the following, if present in a urine sample, would likely be caused by trauma? Choose one answer. a. salts Incorrect b. glucose Incorrect c. amino acids Incorrect d. vitamins Incorrect e. erythrocytes Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of these stimulate the production of red blood cells? Choose one answer. a. epinephrine Incorrect b. low-density lipoproteins Incorrect c. immunoglobulins Incorrect d. platelets Incorrect e. erythropoietin Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 The human X and Y chromosomes Choose one answer. a. are both present in every somatic cell of males and females alike. Incorrect b. include only genes that govern sex determination. Incorrect c. are almost entirely homologous, despite their different names. Incorrect d. are of approximately equal size and number of genes. Incorrect e. include genes that determine an individual's sex. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of Choose one answer. a. a cline. Correct b. genetic drift. Incorrect c. relative fitness. Incorrect d. geographic variation. Incorrect e. a bottleneck. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method. Answer: True Correct False Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following is a statement of the first law of thermodynamics? Choose one answer. a. The entropy of the universe is decreasing. Incorrect b. Energy cannot be created or destroyed. Correct c. The entropy of the universe is constant. Incorrect d. Energy cannot be transferred or transformed. Incorrect e. Kinetic energy is stored energy that results from the specific arrangement of matter. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Cells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. Which of the following are part of the cytoskeleton? Choose one answer. a. microfilaments Incorrect b. mitochondria Incorrect c. lysosomes Incorrect d. nucleoli Incorrect e. the nuclear envelope Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 How is most of the carbon dioxide transported by the blood in humans? Choose one answer. a. CO2 dissolved in the plasma Incorrect b. bicarbonate ions in the plasma Correct c. bicarbonate attached to hemoglobin Incorrect d. carbonic acid in the erythrocytes Incorrect e. CO2 attached to hemoglobin Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 The MPF protein complex turns itself off by Choose one answer. a. activating a process that destroys cyclin component. Correct b. exiting the cell. Incorrect c. activating an enzyme that stimulates cyclin. Incorrect d. binding to chromatin. Incorrect e. activating the anaphase-promoting complex. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 A group of students was designing an experiment to test the effect of smoking on grass frogs. They hypothesized that to keep the frogs in a smoke-filled environment for defined periods would result in lung cancer in the animals. However, when they searched for previously published information to shore up their hypothesis, they discovered they were quite wrong in their original assessment. Even though they were never going to go ahead with their experiment (so as not to harm frogs needlessly) they knew that a more likely outcome would be which of the following? Choose one answer. a. the amphibian equivalent of hypertension Incorrect b. diminished absorption of oxygen Incorrect c. skin cancer Correct d. gill abnormalities in the next generation of tadpoles Incorrect e. tracheal tube abnormalities Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply? Choose one answer. a. Photosystem II must have been selected against in some species. Incorrect b. Cyclic flow must be more primitive than linear flow of electrons. Incorrect c. Photosystem I must be more ancestral. Correct d. Photosystem II may have evolved to be more photoprotective. Incorrect e. Cyclic flow must be the most necessary of the two processes. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. a. the concentration of H+ ions in the water is 7 times the concentration of OH- ions in the water. Incorrect b. there are no H+ ions in the water. Incorrect c. there are no OH- ions in the water. Incorrect d. The concentration of OH- ions in the water is 7 times the concentration of H+ ions in the water. Incorrect e. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of these speed up heart rate? Choose one answer. a. platelets Incorrect b. erythropoietin Incorrect c. low-density lipoproteins Incorrect d. immunoglobulins Incorrect e. epinephrine Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? Choose one answer. a. a mouse species living in the desert Correct b. a river otter Incorrect c. a beaver Incorrect d. a mouse species living in a temperate broadleaf forest Incorrect e. a mouse species living in a tropical rain forest Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be Choose one answer. a. x. Incorrect b. 2x. Correct c. 0.5x. Incorrect d. 0.25x. Incorrect e. 4x. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which of the following organelles functions in this compartmentalization? Choose one answer. a. chloroplast Incorrect b. glyoxysome Incorrect c. peroxisome Incorrect d. lysosome Correct e. central vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found? Choose one answer. a. feedback inhibition Incorrect b. an enzyme with more than one subunit Correct c. both activating and inhibitory activity Incorrect d. the need for cofactors Incorrect e. cooperativity Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 An obstetrician knows that one of her patients is a pregnant woman whose fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the following procedures to her patient? Choose one answer. a. CVS Incorrect b. X-ray Incorrect c. Amniocentesis Correct d. Fetoscopy Incorrect e. Ultrasound imaging Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The mammalian trachea and esophagus both connect to the Choose one answer. a. rectum. Incorrect b. epiglottis. Incorrect c. stomach. Incorrect d. pharynx. Correct e. large intestine. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. muscle and liver glycogen Correct b. fat stored in adipose tissue Incorrect c. blood proteins Incorrect d. muscle proteins Incorrect e. fat stored in the liver Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 To leave the digestive tract, a substance must cross a cell membrane. During which stage of food processing does this take place? Choose one answer. a. digestion Incorrect b. ingestion Incorrect c. elimination Incorrect d. absorption Correct e. hydrolysis Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Obesity in humans is most likely to contribute to which of the following? Choose one answer. a. type II diabetes and cardiovascular disease Correct b. type I diabetes and prostate cancer Incorrect c. type II diabetes and muscle atrophy Incorrect d. type I diabetes and breast cancer Incorrect e. type II diabetes and decreased insulin production Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. ADP. Incorrect b. pyruvate. Incorrect c. NAD+. Incorrect d. oxygen. Correct e. water. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? Choose one answer. a. water's high surface tension Incorrect b. water's change in density when it condenses Incorrect c. the absorption of heat by the breaking of hydrogen bonds Correct d. water's ability to dissolve molecules in the air Incorrect e. the release of heat by the formation of hydrogen bonds Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 The pH of the gastric juice of the stomach is about 2 due to the formation of HCl. Where does this formation of HCl occur? Choose one answer. a. in the lumen of the stomach Correct b. in the chief cells of the stomach Incorrect c. in the transformation of pepsinogen to pepsin Incorrect d. in the secretions of the esophagus Incorrect e. in the parietal cells of the stomach Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Synthesis of ATP by the chemiosmotic mechanism occurs during Choose one answer. a. photorespiration. Incorrect b. both photosynthesis and respiration. Correct c. neither photosynthesis nor respiration. Incorrect d. photosynthesis. Incorrect e. respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites? Choose one answer. a. There were fewer kinds of amino acids on the chondrites than are found in living organisms today. Incorrect b. They had the same proportion of L and D isomers as Earth does today. Incorrect c. They were delivered in the form of polypeptides. Incorrect d. The proportion of the amino acids was similar to those produced in the Miller-Urey experiment. Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. H2O ? NADPH ? Calvin cycle Correct b. H2O ? photosystem I ? photosystem II Incorrect c. NADPH ? O2 ? CO2 Incorrect d. NADPH ? electron transport chain ? O2 Incorrect e. NADPH ? chlorophyll ? Calvin cycle Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. oxidation of pyruvate to acetyl CoA Incorrect b. oxidative phosphorylation Incorrect c. glycolysis and fermentation Correct d. citric acid cycle Incorrect e. fermentation and chemiosmosis Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result? Choose one answer. a. The gene involved is on the Y chromosome. Incorrect b. The gene involved is on an autosome. Incorrect c. Other male-specific factors influence eye color in flies. Incorrect d. The gene involved is on the X chromosome. Correct e. Other female-specific factors influence eye color in flies. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? Choose one answer. a. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. Incorrect b. There is no consistent relationship. Incorrect c. The pH of the stroma is higher than that of the other two measurements. Incorrect d. The pH of the thylakoid space is higher than that anywhere else in the cell. Incorrect e. The pH within the thylakoid is less than that of the stroma. Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Systems biology is mainly an attempt to Choose one answer. a. simplify complex problems by reducing the system into smaller, less complex units. Incorrect b. understand the integration of all levels of biological organization from molecules to the biosphere. Incorrect c. build high-throughput machines for the rapid acquisition of biological data. Incorrect d. construct models of the behavior of entire biological systems. Correct e. speed up the technological application of scientific knowledge. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which statement about natural selection is most correct? Choose one answer. a. Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes. Incorrect b. Natural selection is the sole means by which populations can evolve. Incorrect c. Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals. Correct d. Adaptations beneficial at one time should generally be beneficial during all other times as well. Incorrect e. Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? Choose one answer. a. 63 chromosomes in 31 1/2 pairs Incorrect b. 21 chromosome pairs and 21 unique chromosomes Incorrect c. 63 chromosomes, each with three chromatids Incorrect d. 63 chromosomes in 21 sets of 3 Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A less-than-normal volume of isoosmotic urine would be produced. Incorrect b. A greater-than-normal volume of isoosmotic urine would be produced. Correct c. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect d. No urine would be produced. Incorrect e. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. insect Incorrect b. annelid Incorrect c. mollusc Incorrect d. fish Incorrect e. frog Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? Choose one answer. a. disruptive selection Incorrect b. sexual selection Incorrect c. stabilizing selection Correct d. artificial selection Incorrect e. directional selection Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Where is ATP synthase located in the mitochondrion? Choose one answer. a. electron transport chain Incorrect b. mitochondrial matrix Incorrect c. outer membrane Incorrect d. inner membrane Correct e. cytosol Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis? Choose one answer. a. All the gametes will be diploid. Incorrect b. 1/4 of the gametes will be n + 1, one will be n — 1, and two will be n. Correct c. Two of the four gametes will be haploid, and two will be diploid. Incorrect d. There will be three extra gametes. Incorrect e. Half of the gametes will be n + 1, and half will be n — 1. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 In addition to ATP, what are the end products of glycolysis? Choose one answer. a. CO2 and H2O Incorrect b. CO2 and NADH Incorrect c. H2O, FADH2, and citrate Incorrect d. CO2 and pyruvate Incorrect e. NADH and pyruvate Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? Choose one answer. a. 5'-A-T-G-C-3' with 5'-G-C-A-T-3' Correct b. 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' Incorrect c. All of these pairs are correct. Incorrect d. 5'-A-G-C-T-3' with 5'-T-C-G-A-3' Incorrect e. 5'-G-C-G-C-3' with 5'-T-A-T-A-3' Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The frequency of crossing over between any two linked genes will be which of the following? Choose one answer. a. Dependent on how many alleles there are Incorrect b. Higher if they are recessive Incorrect c. Proportional to the distance between them Correct d. Determined by their relative dominance Incorrect e. The same as if they were not linked Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following types of molecules are the major structural components of the cell membrane? Choose one answer. a. phospholipids and cellulose Incorrect b. nucleic acids and proteins Incorrect c. phospholipids and proteins Correct d. glycoproteins and cholesterol Incorrect e. proteins and cellulose Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 19 Started on Saturday, January 17, 2009, 10:35 AM Completed on Saturday, January 17, 2009, 10:35 AM Time taken 8 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 What would account for increased urine production as a result of drinking alcoholic beverages? Choose one answer. a. increased reabsorption of water in the proximal tubule Incorrect b. inhibition of antidiuretic hormone secretion (ADH) Correct c. increased aldosterone production Incorrect d. the osmoregulator cells of the brain increasing their activity Incorrect e. increased blood pressure Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 What is a chromatid? Choose one answer. a. a replicate chromosome Correct b. a chromosome found outside the nucleus Incorrect c. a chromosome in G1 of the cell cycle Incorrect d. a special region that holds two centromeres together Incorrect e. another name for the chromosomes found in genetics Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following ionizes completely in solution and is considered to be a strong acid? Choose one answer. a. NaOH Incorrect b. H2CO3 Incorrect c. CH3COOH Incorrect d. NH3 Incorrect e. HCl Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 An obstetrician knows that one of her patients is a pregnant woman whose fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the following procedures to her patient? Choose one answer. a. Ultrasound imaging Incorrect b. CVS Incorrect c. Fetoscopy Incorrect d. X-ray Incorrect e. Amniocentesis Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect b. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect c. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect d. protein function at one site affected by binding at another of its active sites Incorrect e. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. kidneys of vertebrates Correct b. Malpighian tubules of insects Incorrect c. flame-bulb system of flatworms Incorrect d. protonephridia of rotifers Incorrect e. metanephridia of earthworms Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. ADP and NADP Incorrect b. ATP and P700 Incorrect c. heat and fluorescence Incorrect d. P700 and P680 Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect b. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect c. There is no possibility of having chemical equilibrium in any living cell. Incorrect d. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect e. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? Choose one answer. a. the lysosome Correct b. membrane-bound ribosomes Incorrect c. the Golgi apparatus Incorrect d. the endoplasmic reticulum Incorrect e. mitochondria Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. +G, +H, -S Correct b. -G, +H, +S Incorrect c. +G, +H, +S Incorrect d. +G, -H, -S Incorrect e. -G, -H, -S Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is used to diagnose hypertension in adults? Choose one answer. a. measurement of the LDL/HDL ratio in peripheral blood Incorrect b. percent of blood volume made up of platelets Incorrect c. measurement of fatty deposits on the endothelium of arteries Incorrect d. number of leukocytes per mm3 of blood Incorrect e. blood pressure of >140 mm Hg systolic and/or >90 diastolic Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? Choose one answer. a. on the outside of vesicles Incorrect b. on the inside surface of the vesicle Correct c. on the outer surface of the nucleus Incorrect d. on the ER Incorrect e. on the inside surface of the cell membrane Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 The symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the Choose one answer. a. small intestine. Incorrect b. pharynx. Incorrect c. stomach. Correct d. liver. Incorrect e. large intestine. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell? Choose one answer. a. prophase Incorrect b. telophase Incorrect c. prometaphase Incorrect d. metaphase Incorrect e. anaphase Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? Choose one answer. a. spending several hours mowing the lawn on a hot day Correct b. drinking several glasses of water Incorrect c. sleeping Incorrect d. eating a pizza with olives and pepperoni Incorrect e. eating a bag of potato chips Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following describe(s) cyclin-dependent kinase (Cdk)? Choose one answer. a. Cdk is present throughout the cell cycle. Incorrect b. Cdk is an enzyme that attaches phosphate groups to other proteins. Incorrect c. Both A and B are true. Incorrect d. Both B and C are true. Correct e. Cdk is inactive, or "turned off," in the presence of cyclin. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Why is it important that an experiment include a control group? Choose one answer. a. A control group assures that an experiment will be repeatable. Incorrect b. A control group is required for the development of an "if, then" statement. Incorrect c. The control group is the group that the researcher is in control of; it is the group in which the researcher predetermines the nature of the results. Incorrect d. Without a control group, there is no basis for knowing if a particular result is due to the variable being tested or to some other factor. Correct e. The control group provides a reserve of experimental subjects. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 A type of protein critical to all cells is organic catalysts called Choose one answer. a. nutrients. Incorrect b. feedback inhibitors. Incorrect c. feedback activators. Incorrect d. enzymes. Correct e. metabolites. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following statements is completely correct? Choose one answer. a. H2CO3 is a weak acid, and NaOH is a weak base (alkali). Incorrect b. NH3 is a weak base (alkali), and H2CO3 is a strong acid. Incorrect c. NH3 is a weak base (alkali), and HCl is a strong acid. Correct d. NH3 is a strong base (alkali), and HCl is a weak acid. Incorrect e. H2CO3 is a strong acid, and NaOH is a strong base (alkali). Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 What is the reducing agent in the following reaction? Pyruvate + NADH + H+ ? Lactate + NAD+ Choose one answer. a. NAD+ Incorrect b. oxygen Incorrect c. lactate Incorrect d. NADH Correct e. pyruvate Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Organic chemistry is a science based on the study of Choose one answer. a. functional groups. Incorrect b. carbon compounds. Correct c. inorganic compounds. Incorrect d. water and its interaction with other kinds of molecules. Incorrect e. vital forces interacting with matter. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 In order to understand the chemical basis of inheritance, one must understand the molecular structure of DNA. This is an example of the application of __________ to the study of biology. Choose one answer. a. reductionism Correct b. the cell theory Incorrect c. emergent properties Incorrect d. evolution Incorrect e. feedback regulation Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. must be ingested in the diet. Incorrect b. is not used by the animal in biosynthesis. Incorrect c. is less important than an essential amino acid. Incorrect d. is not found in many proteins. Incorrect e. can be made by the animal's body from other substances. Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes prevent changes in substrate concentrations. Incorrect b. Enzymes are permanently altered by the reactions they catalyze. Incorrect c. Enzymes change the direction of chemical reactions. Incorrect d. Enzymes decrease the free energy change of a reaction. Incorrect e. Enzymes increase the rate of a reaction. Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. oxygen and carbon dioxide Incorrect b. carbon dioxide and RuBP Incorrect c. ATP and NADPH Correct d. electrons and photons Incorrect e. water and carbon Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Two species that belong to the same genus must also belong to the same Choose one answer. a. order. Incorrect b. phylum. Incorrect c. class. Incorrect d. all of the above Correct e. kingdom. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? Choose one answer. a. producers and primary consumers Incorrect b. autotrophs Correct c. autotrophs and heterotrophs Incorrect d. green plants Incorrect e. photosynthesizers Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes? Choose one answer. a. 25% Incorrect b. 75% Incorrect c. 50% Incorrect d. 0% Incorrect e. 100% Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They are easily reduced. Incorrect b. They can have very long carbon skeletons. Incorrect c. They have a lot of electrons associated with hydrogen. Correct d. They have no nitrogen in their makeup. Incorrect e. They have a lot of oxygen atoms. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which describes the ABO blood group system? Choose one answer. a. Pleiotropy Incorrect b. Epistasis Incorrect c. Multiple alleles Correct d. Incomplete dominance Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following is (are) true for anabolic pathways? Choose one answer. a. They do not depend on enzymes. Incorrect b. They release energy as they degrade polymers to monomers. Incorrect c. They consume energy to build up polymers from monomers. Correct d. They are usually highly spontaneous chemical reactions. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Where are the proteins of the electron transport chain located? Choose one answer. a. mitochondrial matrix Incorrect b. mitochondrial outer membrane Incorrect c. mitochondrial intermembrane space Incorrect d. cytosol Incorrect e. mitochondrial inner membrane Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. transfers large molecules as easily as small ones. Incorrect b. results from active transport. Incorrect c. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect d. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct e. is very selective as to which subprotein sized molecules are transferred. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? Choose one answer. a. The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. Correct b. There is no relationship between the light reactions and the Calvin cycle. Incorrect c. The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. Incorrect d. The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. Incorrect e. The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this? Choose one answer. a. stabilizing selection Incorrect b. directional selection Correct c. sexual selection Incorrect d. artificial selection Incorrect e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 What is the voltage across a membrane called? Choose one answer. a. membrane potential Correct b. osmotic potential Incorrect c. water potential Incorrect d. chemical gradient Incorrect e. electrochemical gradient Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following is measured by an electrocardiogram? Choose one answer. a. impulses of the parasympathetic nervous system that control heart beat Incorrect b. impulses from the AV node Incorrect c. the spread of impulses from the SA node Correct d. systole and diastole Incorrect e. contraction of the two atria Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 What is the source of the extra chromosome 21 in an individual with Down syndrome? Choose one answer. a. Nondisjunction in the father only Incorrect b. Nondisjunction in the mother only Incorrect c. Nondisjunction or translocation in either parent Correct d. It is impossible to detect with current technology Incorrect e. Duplication of the chromosome Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Air rushes into the lungs of humans during inhalation because Choose one answer. a. gas flows from a region of lower pressure to a region of higher pressure. Incorrect b. pulmonary muscles contract and pull on the outer surface of the lungs. Incorrect c. a positive respiratory pressure is created when the diaphragm relaxes. Incorrect d. pressure in the alveoli increases. Incorrect e. the rib muscles and diaphragm contract, increasing the lung volume. Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 One liter of a solution pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4? Choose one answer. a. 1,000 times more Incorrect b. 100 times more Incorrect c. 10,000 times more Incorrect d. 5 times more Incorrect e. 100,000 times more Correct Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect b. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect c. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect d. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct e. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. H2O and NADPH. Incorrect b. CO2 and ATP. Incorrect c. sugar and O2. Incorrect d. ATP and NADPH. Correct e. light energy. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following minerals is associated with its use in animals? Choose one answer. a. calciumconstruction and maintenance of bone Correct b. ironnecessary for thyroid function Incorrect c. sulfuringredient of nucleic acids Incorrect d. iodineimportant in nerve function Incorrect e. magnesiumcofactor in enzymes that make ATP Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following is an advantage of a complete digestive system over a gastrovascular cavity? Choose one answer. a. Extracellular digestion is not needed. Incorrect b. Specialized regions are possible. Correct c. Intracellular digestion is easier. Incorrect d. Digestive enzymes can be more specific. Incorrect e. Extensive branching is possible. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. insect Incorrect b. frog Correct c. mollusc Incorrect d. annelid Incorrect e. fish Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? Choose one answer. a. PDGF Incorrect b. MPF Incorrect c. cyclin Incorrect d. Cdk Correct e. protein kinase Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 During which phases of mitosis are chromosomes composed of two chromatids? Choose one answer. a. from G2 of interphase through metaphase Correct b. from interphase through anaphase Incorrect c. from G1 of interphase through metaphase Incorrect d. from anaphase through telophase Incorrect e. from metaphase through telophase Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction Choose one answer. a. gains electrons and loses energy. Incorrect b. loses electrons and gains energy. Incorrect c. loses electrons and loses energy. Correct d. neither gains nor loses electrons, but gains or loses energy. Incorrect e. gains electrons and gains energy. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Recent evidence points to the conclusion that the ancestral finches of the Galapagos originated in the islands of the Caribbean. Answer: True Correct False Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following is the correct sequence of these events in the origin of life? I. formation of protobionts II. synthesis of organic monomers III. synthesis of organic polymers IV. formation of DNA-based genetic systems Choose one answer. a. I, II, III, IV Incorrect b. I, III, II, IV Incorrect c. IV, III, I, II Incorrect d. III, II, I, IV Incorrect e. II, III, I, IV Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Which of the following processes includes all others? Choose one answer. a. facilitated diffusion Incorrect b. passive transport Correct c. diffusion of a solute across a membrane Incorrect d. transport of an ion down its electrochemical gradient Incorrect e. osmosis Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? Choose one answer. a. sexual selection Incorrect b. stabilizing selection Correct c. disruptive selection Incorrect d. directional selection Incorrect e. artificial selection Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect b. It may explain the transmission of Duchenne muscular dystrophy. Incorrect c. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect d. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which statement about natural selection is most correct? Choose one answer. a. Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well. Incorrect b. Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals. Correct c. Natural selection is the sole means by which populations can evolve. Incorrect d. Adaptations beneficial at one time should generally be beneficial during all other times as well. Incorrect e. Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following are capable of converting light energy to chemical energy? Choose one answer. a. Golgi bodies Incorrect b. mitochondria Incorrect c. leucoplasts Incorrect d. chloroplasts Correct e. peroxisomes Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Which structure passes urine to the renal pelvis? Choose one answer. a. Bowman's capsule Incorrect b. proximal tubule Incorrect c. collecting duct Correct d. glomerulus Incorrect e. loop of Henle Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following are nitrogenous bases of the purine type? Choose one answer. a. adenine and thymine Incorrect b. cytosine and guanine Incorrect c. guanine and adenine Correct d. thymine and uracil Incorrect e. uracil and cytosine Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 It is possible to prepare vesicles from portions of the inner membrane of the mitochondrial components. Which one of the following processes could still be carried on by this isolated inner membrane? Choose one answer. a. both the citric acid cycle and oxidative phosphorylation Incorrect b. glycolysis and fermentation Incorrect c. oxidative phosphorylation Correct d. reduction of NAD+ Incorrect e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Which of the following is not an observation or inference on which natural selection is based? Choose one answer. a. Species produce more offspring than the environment can support. Incorrect b. There is heritable variation among individuals. Incorrect c. Only a fraction of the offspring produced by an individual may survive. Incorrect d. Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less suited. Incorrect e. Poorly adapted individuals never produce offspring. Correct Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon increase. Incorrect b. Thyroid hormone is increased. Incorrect c. Blood insulin increases. Incorrect d. Blood glucagon increases. Correct e. Both insulin and glucagon decrease. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 20 Started on Saturday, January 17, 2009, 10:35 AM Completed on Saturday, January 17, 2009, 10:36 AM Time taken 9 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Which of the following is released by platelets in the vicinity of an injury? Choose one answer. a. MPF Incorrect b. PDGF Correct c. Cdk Incorrect d. protein kinase Incorrect e. cyclin Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean? Choose one answer. a. Cells with proton pumps were maintained in each Kingdom by natural selection. Correct b. Proton pumps are fundamental to all cell types. Incorrect c. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. Incorrect d. Proton pumps must have evolved before any living organisms were present on the earth. Incorrect e. Proton pumps are necessary to all cell membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle? Choose one answer. a. 2 ATP, 2 CO2, 1 NADH, and 3 FADH2 Incorrect b. 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 Incorrect c. 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 Correct d. 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 Incorrect e. 38 ATP, 6 CO2, 3 NADH, and 12 FADH2 Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The frequency of crossing over between any two linked genes will be which of the following? Choose one answer. a. The same as if they were not linked Incorrect b. Proportional to the distance between them Correct c. Dependent on how many alleles there are Incorrect d. Higher if they are recessive Incorrect e. Determined by their relative dominance Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 At which level of protein structure are interactions between the side chains (R groups) most important? Choose one answer. a. primary Incorrect b. secondary Incorrect c. tertiary Correct d. all of the above Incorrect e. quaternary Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the Choose one answer. a. reduction of NAD+. Incorrect b. restoration of the Na+/K+ balance across the membrane. Incorrect c. creation of a proton gradient. Correct d. lowering of pH in the mitochondrial matrix. Incorrect e. formation of ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a Choose one answer. a. CAM plant. Incorrect b. C4 plant. Correct c. chemoautotroph. Incorrect d. heterotroph. Incorrect e. C3 plant. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 In a hypothetical world, every 50 years people over 6 feet tall are eliminated from the population. Based on your knowledge of natural selection, you would predict that the average height of the human population will Choose one answer. a. rapidly decline. Incorrect b. gradually decline. Correct c. rapidly increase. Incorrect d. remain unchanged. Incorrect e. gradually increase. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 A hiatal hernia affects the function of the smooth muscle between the esophagus and the stomach. The hernia would be most likely to increase the frequency of which of the following? Choose one answer. a. increased stomach pH Incorrect b. premature entry of food into the duodenum Incorrect c. gastric reflux Correct d. retention of food in the stomach Incorrect e. excess secretion of pepsinogen Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following are directly associated with photosystem I? Choose one answer. a. harvesting of light energy by ATP Incorrect b. P680 reaction-center chlorophyll Incorrect c. extraction of hydrogen electrons from the splitting of water Incorrect d. receiving electrons from plastocyanin Correct e. passing electrons to plastoquinone Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 The transfer of fluid from the glomerulus to Bowman's capsule Choose one answer. a. is very selective as to which subprotein sized molecules are transferred. Incorrect b. transfers large molecules as easily as small ones. Incorrect c. usually includes the transfer of red blood cells to the Bowman's capsule. Incorrect d. results from active transport. Incorrect e. is mainly a consequence of blood pressure in the capillaries of the glomerulus Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? Choose one answer. a. As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth. Correct b. Living organisms do not follow the laws of thermodynamics. Incorrect c. Life obeys the second law of thermodynamics because the decrease in entropy as the organism grows is balanced by an increase in the entropy of the universe. Incorrect d. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. Incorrect e. Living organisms are able to transform energy into entropy. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following statements describes pepsin? Choose one answer. a. It splits maltose into monosaccharides. Incorrect b. It helps stabilize fat-water emulsions. Incorrect c. It is denatured and rendered inactive in solutions with low pH. Incorrect d. It begins the hydrolysis of proteins in the stomach. Correct e. It is manufactured by the pancreas. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following? Choose one answer. a. His discussions of heredity with his colleagues at major universities Incorrect b. The understanding of particulate inheritance he learned from renowned scientists of his time Incorrect c. His reading and discussion of Darwin's Origin of Species Incorrect d. His reading of the scientific literature current in the field Incorrect e. His experiments with the breeding of plants such as peas Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct b. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect c. Every cell is enclosed by a membrane. Incorrect d. Every cell uses DNA as its genetic information. Incorrect e. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? Choose one answer. a. eating a bag of potato chips Incorrect b. spending several hours mowing the lawn on a hot day Correct c. drinking several glasses of water Incorrect d. sleeping Incorrect e. eating a pizza with olives and pepperoni Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Whenever energy is transformed, there is always an increase in the Choose one answer. a. entropy of the universe. Correct b. enthalpy of the universe. Incorrect c. entropy of the system. Incorrect d. free energy of the system. Incorrect e. free energy of the universe. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Microbial symbionts are especially important for nutritional support in which of the following? Choose one answer. a. herbivores and carnivores Incorrect b. herbivores and omnivores Correct c. animals without an esophagus Incorrect d. animals with large stomach and short intestines Incorrect e. carnivores and omnivores Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Research indicates that Albuterol, a drug used to relax bronchial muscles, improving airflow and thus offering relief from asthma, consists only of one enantiomer, the R-form. Why is it important for this drug to consist of only one enantiomeric form, rather than a mixture of enantiomers? Choose one answer. a. Only the R-form of Albuterol has been studied; until more information is available, physicians prefer to use the pure R-form. Incorrect b. Different enantiomers may have different or opposite physiological effects. Correct c. Albuterol is an example of a compound for which only one enantiomer exists. Incorrect d. It is impossible to synthesize mixtures of enantiomers. Incorrect e. It is much less expensive to synthesize one enantiomer at a time. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. prometaphase Incorrect b. anaphase Incorrect c. telophase Incorrect d. metaphase Correct e. prophase Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? Choose one answer. a. phylogenetic Incorrect b. ecological Incorrect c. biological Incorrect d. morphological Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. metanephridia of earthworms Incorrect b. Malpighian tubules of insects Incorrect c. kidneys of vertebrates Correct d. protonephridia of rotifers Incorrect e. flame-bulb system of flatworms Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 In negative pressure breathing, inhalation results from Choose one answer. a. forcing air from the throat down into the lungs. Incorrect b. contracting the abdominal muscles. Incorrect c. relaxing the muscles of the rib cage. Incorrect d. contracting the diaphragm. Correct e. using muscles of the lungs to expand the alveoli. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 As a young biologist, Charles Darwin had expected the living plants of temperate South America would resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explanation for this observation is most properly associated with the field of Choose one answer. a. biogeography. Correct b. vertebrate anatomy. Incorrect c. meteorology. Incorrect d. bioengineering. Incorrect e. embryology. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution? Choose one answer. a. neutral Correct b. basic: H+ donor Incorrect c. basic: H+ acceptor Incorrect d. acidic: H+ donor Incorrect e. acidic: H+ acceptor Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following mechanisms for osmoregulation or nitrogen removal is correctly paired with its corresponding animal? Choose one answer. a. kidney-insect Incorrect b. metanephridium-flatworm Incorrect c. flame bulb-snake Incorrect d. direct cellular exchange-marine invertebrate Correct e. Malpighian tubule-frog Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 What is the voltage across a membrane called? Choose one answer. a. chemical gradient Incorrect b. osmotic potential Incorrect c. electrochemical gradient Incorrect d. membrane potential Correct e. water potential Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? Choose one answer. a. dehydration Incorrect b. catalysis Incorrect c. metabolism Incorrect d. catabolism Correct e. anabolism Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following is an example of hydrolysis? Choose one answer. a. the reaction of a fat, forming glycerol and fatty acids with the utilization of water Correct b. the synthesis of two amino acids, forming a peptide with the release of water Incorrect c. the reaction of two monosaccharides, forming a disaccharide with the release of water Incorrect d. the reaction of a fat, forming glycerol and fatty acids with the release of water Incorrect e. the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe? Choose one answer. a. Infectious inheritance Incorrect b. Chloroplast inheritance Correct c. Genomic imprinting Incorrect d. Sex-linkage Incorrect e. Mitochondrial inheritance Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of these stimulate the production of red blood cells? Choose one answer. a. erythropoietin Correct b. low-density lipoproteins Incorrect c. immunoglobulins Incorrect d. platelets Incorrect e. epinephrine Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. water and carbon Incorrect b. ATP and NADPH Correct c. electrons and photons Incorrect d. oxygen and carbon dioxide Incorrect e. carbon dioxide and RuBP Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests Choose one answer. a. that the parents were true-breeding for contrasting traits. Incorrect b. that a blending of traits has occurred. Incorrect c. that each offspring has the same alleles. Incorrect d. that the parents were both heterozygous. Correct e. incomplete dominance. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following is a true distinction between fermentation and cellular respiration? Choose one answer. a. Fermentation, but not respiration, is an example of a catabolic pathway. Incorrect b. Substrate-level phosphorylation is unique to fermentation. Incorrect c. NADH is oxidized by the electron transport chain in respiration only. Correct d. Only respiration oxidizes glucose. Incorrect e. NAD+ functions as an oxidizing agent only in respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have which of the following? Choose one answer. a. an open circulatory system Incorrect b. hemolymph Incorrect c. a gastrovascular cavity Incorrect d. branched tracheae Incorrect e. a closed circulatory system Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. intestine Incorrect b. liver Incorrect c. stomach Correct d. gallbladder Incorrect e. pancreas Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 A pedigree analysis for a given disorder's occurrence in a family shows that, although both parents of an affected child are normal, each of the parents has had affected relatives with the same condition. The disorder is then which of the following? Choose one answer. a. A new mutation Incorrect b. Recessive Correct c. Incompletely dominant Incorrect d. Dominant Incorrect e. Maternally inherited Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following features do all gas exchange systems have in common? Choose one answer. a. They are maintained at a constant temperature. Incorrect b. The exchange surfaces are moist. Correct c. They are exposed to air. Incorrect d. They are enclosed within ribs. Incorrect e. They are found only in animals. Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? Choose one answer. a. Breed this plant with another plant with much weaker traits. Incorrect b. Backtrack through her previous experiments to obtain another plant with the same traits. Incorrect c. Add nitrogen to the soil of the offspring of this plant so the desired traits continue. Incorrect d. Force the plant to self-pollinate to obtain an identical one. Incorrect e. Clone the plant asexually to produce an identical one. Correct Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which is the longest of the mitotic stages? Choose one answer. a. prophase Incorrect b. metaphase Correct c. prometaphase Incorrect d. telophase Incorrect e. anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? Choose one answer. a. green plants Incorrect b. autotrophs Correct c. producers and primary consumers Incorrect d. autotrophs and heterotrophs Incorrect e. photosynthesizers Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Two species that belong to the same genus must also belong to the same Choose one answer. a. phylum. Incorrect b. class. Incorrect c. order. Incorrect d. all of the above Correct e. kingdom. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following would probably contribute to constipation? A substance that Choose one answer. a. contains plenty of fiber. Incorrect b. stimulates peristalsis. Incorrect c. decreases water reabsorption in the large intestine. Incorrect d. speeds up movement of material in the large intestine. Incorrect e. promotes water reabsorption in the large intestine. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following processes includes all others? Choose one answer. a. passive transport Correct b. facilitated diffusion Incorrect c. diffusion of a solute across a membrane Incorrect d. transport of an ion down its electrochemical gradient Incorrect e. osmosis Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? Choose one answer. a. photosystem II Incorrect b. cyclic electron flow Correct c. chlorophyll Incorrect d. photosystem I Incorrect e. linear electron flow Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following pairs of structures is least likely to represent homology? Choose one answer. a. The wings of a bird and those of an insect Correct b. The wings of a bat and the arms of a human Incorrect c. The brain of a cat and that of a dog Incorrect d. The mitochondria of a plant and those of an animal Incorrect e. The hemoglobin of a baboon and that of a gorilla Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen? Choose one answer. a. lysosome Incorrect b. peroxisome Correct c. mitochondrion Incorrect d. vacuole Incorrect e. Golgi apparatus Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A type of protein critical to all cells is organic catalysts called Choose one answer. a. metabolites. Incorrect b. nutrients. Incorrect c. feedback activators. Incorrect d. feedback inhibitors. Incorrect e. enzymes. Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which of the following is an example of potential rather than kinetic energy? Choose one answer. a. water rushing over Niagara Falls Incorrect b. an insect foraging for food Incorrect c. a firefly using light flashes to attract a mate Incorrect d. a food molecule made up of energy-rich macromolecules Correct e. a boy mowing grass Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following is true of integral membrane proteins? Choose one answer. a. They are not mobile within the bilayer. Incorrect b. They are usually transmembrane proteins. Correct c. They lack tertiary structure. Incorrect d. They are loosely bound to the surface of the bilayer. Incorrect e. They serve only a structural role in membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. Answer: True False Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following reactions prevails in red blood cells traveling through alveolar capillaries? (Hb = hemoglobin) Choose one answer. a. Hb + 4 O2 ? Hb(O2)4 Correct b. Hb(O2)4 ? Hb + 4 O2 Incorrect c. CO2 + H2O ? H2CO3 Incorrect d. H2CO3 ? H+ + HCO3- Incorrect e. Hb + 4 CO2 ? Hb(CO2)4 Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Referring to a plant sexual life cycle, which of the following terms describes the process that leads directly to the formation of gametes? Choose one answer. a. Gametophyte mitosis Correct b. Gametophyte meiosis Incorrect c. Alternation of generations Incorrect d. Sporophyte mitosis Incorrect e. Sporophyte meiosis Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the events described below agrees with the idea of catastrophism? Choose one answer. a. The sudden demise of the dinosaurs, and various other groups, by the impact of a large extraterrestrial body with Earth Correct b. The gradual uplift of the Himalayas by the collision of the Australian crustal plate with the Eurasian crustal plate Incorrect c. The development of the Galapagos Islands from underwater seamounts over millions of years Incorrect d. The gradual deposition of sediments many kilometers thick on the floors of seas and oceans Incorrect e. The formation of the Grand Canyon by the Colorado River over millions of years Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. collecting duct Incorrect b. loop of Henle Incorrect c. Bowman's capsule Incorrect d. vasa recta Correct e. proximal tubule Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Starting with one molecule of glucose, the "net" products of glycolysis are Choose one answer. a. 6 CO2, 6 H2O, 36 ATP, and 2 citrate. Incorrect b. 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. Correct c. 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O. Incorrect d. 6 CO2, 6 H2O, 2 ATP, and 2 pyruvate. Incorrect e. 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Organic chemistry is a science based on the study of Choose one answer. a. inorganic compounds. Incorrect b. carbon compounds. Correct c. vital forces interacting with matter. Incorrect d. functional groups. Incorrect e. water and its interaction with other kinds of molecules. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of the following types of reactions would decrease the entropy within a cell? Choose one answer. a. respiration Incorrect b. hydrolysis Incorrect c. dehydration reactions Correct d. catabolism Incorrect e. digestion Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 If two modern organisms are distantly related in an evolutionary sense, then one should expect that Choose one answer. a. they should be members of the same genus. Incorrect b. they should share fewer homologous structures than two more closely related organisms. Correct c. they live in very different habitats. Incorrect d. they shared a common ancestor relatively recently. Incorrect e. their chromosomes should be very similar. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 9 Weeks Exam Practice Review of Attempt 21 Started on Saturday, January 17, 2009, 10:36 AM Completed on Saturday, January 17, 2009, 10:37 AM Time taken 1 min 18 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 The oxygen consumed during cellular respiration is involved directly in which process or event? Choose one answer. a. the phosphorylation of ADP to form ATP Incorrect b. accepting electrons at the end of the electron transport chain Correct c. the oxidation of pyruvate to acetyl CoA Incorrect d. glycolysis Incorrect e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, taxol must affect Choose one answer. a. the S phase of the cell cycle. Incorrect b. anaphase. Incorrect c. the fibers of the mitotic spindle. Correct d. formation of the centrioles. Incorrect e. chromatid assembly. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Natural selection changes allele frequencies in populations because some __________ survive and reproduce more successfully than others. Choose one answer. a. gene pools Incorrect b. species Incorrect c. individuals Correct d. alleles Incorrect e. loci Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do? Choose one answer. a. transport protons within the mitochondria and chloroplasts Incorrect b. act as reducing agents Incorrect c. donate electrons Incorrect d. act as oxidizing agents Incorrect e. both oxidize and reduce during electron transport Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 A theory in science is equivalent in scope to a well-structured hypothesis. Answer: True False Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect b. A less-than-normal volume of isoosmotic urine would be produced. Incorrect c. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect d. A greater-than-normal volume of isoosmotic urine would be produced. Correct e. No urine would be produced. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is a code for the sequence of amino acids in a protein. Incorrect b. DNA is composed of chemical building blocks called nucleotides. Incorrect c. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect d. Genes are composed of deoxyribonucleic acid. Incorrect e. DNA is an enzyme that puts together amino acids to make a protein. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. fat stored in adipose tissue Incorrect b. blood proteins Incorrect c. muscle and liver glycogen Correct d. fat stored in the liver Incorrect e. muscle proteins Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following is a major cause of the size limits for certain types of cells? Choose one answer. a. the evolution of larger cells after the evolution of smaller cells Incorrect b. the difference in plasma membranes between prokaryotes and eukaryotes Incorrect c. the observation that longer cells usually have greater cell volume Incorrect d. the evolution of eukaryotes after the evolution of prokaryotes Incorrect e. the need for a surface area of sufficient area to allow the cell's function Correct Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 What is the structural feature that allows DNA to replicate? Choose one answer. a. three-component structure of the nucleotides Incorrect b. disulfide bonding (bridging) of the two helixes Incorrect c. complementary pairing of the nitrogenous bases Correct d. sugar-phosphate backbone Incorrect e. twisting of the molecule to form an a helix Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. NADH Incorrect b. FADH2 Correct c. NAD+ Incorrect d. ATP Incorrect e. ADP + Pi Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? Choose one answer. a. 6 Incorrect b. 2 Correct c. 10 Incorrect d. 4 Incorrect e. 8 Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? Choose one answer. a. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate. Correct b. The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. Incorrect c. The sea star was stressed and needed more time to acclimate to new conditions. Incorrect d. The cells of the sea star dehydrated and lost the ability to metabolize. Incorrect e. The contractile vacuoles used to regulate water content ruptured in the freshwater. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Which of the following would contain blood in a normally functioning nephron? Choose one answer. a. loop of Henle Incorrect b. proximal tubule Incorrect c. Bowman's capsule Incorrect d. vasa recta Correct e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? Choose one answer. a. chromatid Incorrect b. centriole Incorrect c. centrosome Correct d. centromere Incorrect e. kinetochore Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? Choose one answer. a. It is used to generate ADP from nucleotide precursors. Incorrect b. It is transported to specific organs such as the brain. Incorrect c. It is used to power yet more cellular work. Incorrect d. It is lost to the environment. Correct e. It is used to store energy as more ATP. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. carbon dioxide and RuBP Incorrect b. water and carbon Incorrect c. electrons and photons Incorrect d. oxygen and carbon dioxide Incorrect e. ATP and NADPH Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 If the pH of a solution is increased from pH 5 to pH 7, it means that the Choose one answer. a. concentration of H+ is 100 times greater and the concentration of OH- is one-hundredth what they were at pH 5. Incorrect b. concentration of OH- is 100 times greater than what it was at pH 5. Correct c. concentration of H+ is half (1/2) what it was at pH 5. Incorrect d. concentration of OH- is one-hundredth (0.01X) what it was at pH 5. Incorrect e. concentration of H+ is twice (2X) what it was at pH 5. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplasts. How would you classify this organism? Choose one answer. a. domain Eukarya, kingdom Protista Incorrect b. domain Eukarya, kingdom Fungi Correct c. domain Eukarya, kingdom Plantae Incorrect d. domain Archaea, kingdom Bacteria Incorrect e. domain Bacteria, kingdom Prokaryota Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. neither photosynthesis nor respiration. Correct b. photorespiration. Incorrect c. respiration. Incorrect d. photosynthesis. Incorrect e. both photosynthesis and respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. blue and violet Correct b. green and yellow Incorrect c. blue, green, and red Incorrect d. red and yellow Incorrect e. green, blue, and yellow Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which of these individuals is most likely to be successful in an evolutionary sense? Choose one answer. a. a male who mates with 20 females and fathers 1 offspring Incorrect b. a reproductively sterile individual who never falls ill Incorrect c. an organism that dies after 5 days of life but leaves 10 offspring, all of whom survive to reproduce Correct d. a female who mates with 20 males and produces 1 offspring Incorrect e. an organism that lives 100 years and leaves 2 offspring, both of whom survive to reproduce Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Who proposed that the membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids? Choose one answer. a. C. Overton Incorrect b. S. Singer and G. Nicolson Correct c. H. Davson and J. Danielli Incorrect d. E. Gorter and F. Grendel Incorrect e. I. Langmuir Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. plasma proteins. Incorrect b. carbonic acid. Incorrect c. carbon dioxide. Incorrect d. hemoglobin. Correct e. plasma buffers. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 A number of systems for pumping across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Small increases in calcium ions in the cytosol trigger a number of different intracellular reactions, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10-7 in a resting cell, while the concentration in the SR can be 10-2, then how is the ATPase acting? Choose one answer. a. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. Correct b. The ATP must be powering an inflow of calcium from the outside of the cell into the SR. Incorrect c. The calcium ions must be diffusing back into the SR along the concentration gradient. Incorrect d. The route of calcium ions must be from SR to the cytosol, to the cell's environment. Incorrect e. ATP must be transferring Pi to the SR to enable this to occur. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following statements about speciation is correct? Choose one answer. a. Speciation is a basis for understanding macroevolution. Correct b. Prezygotic reproductive barriers usually evolve before postzygotic barriers. Incorrect c. Natural selection chooses the reproductive barriers for populations. Incorrect d. When reunited, two allopatric populations will not interbreed. Incorrect e. The goal of natural selection is speciation. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 A hiatal hernia affects the function of the smooth muscle between the esophagus and the stomach. The hernia would be most likely to increase the frequency of which of the following? Choose one answer. a. gastric reflux Correct b. excess secretion of pepsinogen Incorrect c. premature entry of food into the duodenum Incorrect d. retention of food in the stomach Incorrect e. increased stomach pH Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which one of the following, if present in a urine sample, would likely be caused by trauma? Choose one answer. a. amino acids Incorrect b. vitamins Incorrect c. glucose Incorrect d. erythrocytes Correct e. salts Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following describe(s) cyclin-dependent kinase (Cdk)? Choose one answer. a. Cdk is an enzyme that attaches phosphate groups to other proteins. Incorrect b. Both A and B are true. Incorrect c. Cdk is present throughout the cell cycle. Incorrect d. Cdk is inactive, or "turned off," in the presence of cyclin. Incorrect e. Both B and C are true. Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Map units on a linkage map cannot be relied upon to calculate physical distances on a chromosome for which of the following reasons? Choose one answer. a. The relationship between recombination frequency and map units is different in every individual. Incorrect b. The gene order on the chromosomes is slightly different in every individual. Incorrect c. Physical distances between genes change during the course of the cell cycle. Incorrect d. The frequency of crossing over varies along the length of the chromosome. Correct e. Linkage map distances are identical between males and females. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Foods eaten by animals are most often composed largely of macromolecules. This requires the animals to have methods for which of the following? Choose one answer. a. dehydration synthesis Incorrect b. regurgitation Incorrect c. elimination Incorrect d. demineralization Incorrect e. enzymatic hydrolysis Correct Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a freshwater bony fish Incorrect b. a salmon in freshwater Incorrect c. a shark inhabiting freshwater Lake Nicaragua Incorrect d. a marine bony fish Correct e. a marine shark Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect b. Every cell is enclosed by a membrane. Incorrect c. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct d. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect e. Every cell uses DNA as its genetic information. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Natural selection and recombination due to crossing over during meiosis I are related in which of the following ways? Choose one answer. a. Most recombinants reproduce less frequently than do non-recombinants. Incorrect b. Recombinants may have combinations of traits that are favored by natural selection. Correct c. Non-recombinant organisms are usually favored by natural selection if there is environmental change. Incorrect d. Recombinants are usually selected against. Incorrect e. Recombination does not affect natural selection. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur? Choose one answer. a. The ATP must first have to attach to the tRNA. Incorrect b. The hydrolysis of the ATP must be needed to allow the amino acid to bind to the synthetase. Incorrect c. The tRNA molecule must have to alter its shape in order to be able to fit into the active site with the other two molecules. Incorrect d. The 3' end of the tRNA must have to be cleaved before it can have an attached amino acid. Incorrect e. The binding of the first two molecules must cause a 3-dimensional change that opens another active site on the enzyme. Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would be the effect? Choose one answer. a. Atria and ventricles would contract at about the same time. Correct b. No apparent effect on heart activity would be observed. Incorrect c. Only the ventricles would contract. Incorrect d. The heart rate would be decreased. Incorrect e. Only the atria would contract. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean? Choose one answer. a. Cells with proton pumps were maintained in each Kingdom by natural selection. Correct b. The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. Incorrect c. Proton pumps are fundamental to all cell types. Incorrect d. Proton pumps must have evolved before any living organisms were present on the earth. Incorrect e. Proton pumps are necessary to all cell membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian islands have different elaborate courtship rituals that involve fighting other males and stylized movements that attract females. What type of reproductive isolation does this represent? Choose one answer. a. temporal isolation Incorrect b. postzygotic barriers Incorrect c. behavioral isolation Correct d. gametic isolation Incorrect e. habitat isolation Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are Choose one answer. a. phospholipids. Incorrect b. cholesterol molecules. Incorrect c. integral proteins. Correct d. peripheral proteins. Incorrect e. carbohydrates. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following statements is true concerning catabolic pathways? Choose one answer. a. They are spontaneous and do not need enzyme catalysis. Incorrect b. They combine molecules into more energy-rich molecules. Incorrect c. They are endergonic. Incorrect d. They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. Correct e. They build up complex molecules such as protein from simpler compounds. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 How is photosynthesis similar in C4 and CAM plants? Choose one answer. a. Both types of plants make most of their sugar in the dark. Incorrect b. In both cases, rubisco is not used to fix carbon initially. Correct c. In both cases, only photosystem I is used. Incorrect d. Both types of plants make sugar without the Calvin cycle. Incorrect e. In both cases, thylakoids are not involved in photosynthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is an example of countercurrent exchange? Choose one answer. a. the flow of water across the skin of a frog and that of blood within the ventricle of its heart Incorrect b. the flow of air within the primary bronchi of a human and that of blood within the pulmonary veins Incorrect c. the flow of fluid out of the arterial end of a capillary and that of fluid back into the venous end of the same capillary Incorrect d. the flow of water across the gills of a fish and that of blood within those gills Correct e. the flow of blood in the dorsal vessel of an insect and that of air within its tracheae Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy? Choose one answer. a. The electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds. Incorrect b. The covalent bond in O2 is unstable and easily broken by electrons from organic molecules. Incorrect c. The oxidation of organic compounds can be used to make ATP. Incorrect d. Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O). Correct e. The covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Altering which of the following levels of structural organization could change the function of a protein? Choose one answer. a. tertiary Incorrect b. all of the above Correct c. quaternary Incorrect d. primary Incorrect e. secondary Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Intracellular digestion of peptides is usually immediately preceded by which process? Choose one answer. a. absorption Incorrect b. secretion Incorrect c. endocytosis Correct d. hydrolysis Incorrect e. elimination Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Water's high specific heat is mainly a consequence of the Choose one answer. a. absorption and release of heat when hydrogen bonds break and form. Correct b. high specific heat of oxygen and hydrogen atoms. Incorrect c. small size of the water molecules. Incorrect d. inability of water to dissipate heat into dry air. Incorrect e. fact that water is a poor heat conductor. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male? Choose one answer. a. Tortoiseshell females; black males Correct b. Orange females; orange males Incorrect c. Orange females; black males Incorrect d. Tortoiseshell females; tortoiseshell males Incorrect e. Black females; orange males Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic of all of these extracellular structures? Choose one answer. a. They are constructed of materials that are largely synthesized in the cytoplasm and then transported out of the cell. Correct b. They must permit information transfer between the cell's cytoplasm and the nucleus. Incorrect c. They are composed of a mixture of lipids and carbohydrates. Incorrect d. They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. Incorrect e. They must block water and small molecules in order to regulate the exchange of matter and energy with their environment. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Some bacteria are metabolically active in hot springs because Choose one answer. a. their enzymes have high optimal temperatures. Correct b. high temperatures make catalysis unnecessary. Incorrect c. their enzymes are completely insensitive to temperature. Incorrect d. they use molecules other than proteins or RNAs as their main catalysts. Incorrect e. they are able to maintain a cooler internal temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Which of the following is released by platelets in the vicinity of an injury? Choose one answer. a. PDGF Correct b. Cdk Incorrect c. protein kinase Incorrect d. MPF Incorrect e. cyclin Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Which of the following observations helped Darwin shape his concept of descent with modification? Choose one answer. a. South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe. Correct b. Earthquakes reshape life by causing mass extinctions. Incorrect c. Fewer species live on islands than on the nearest continents. Incorrect d. Species diversity declines farther from the equator. Incorrect e. Birds can be found on islands located farther from the mainland than the birds' maximum nonstop flight distance. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 A pedigree analysis for a given disorder's occurrence in a family shows that, although both parents of an affected child are normal, each of the parents has had affected relatives with the same condition. The disorder is then which of the following? Choose one answer. a. Incompletely dominant Incorrect b. Dominant Incorrect c. Recessive Correct d. A new mutation Incorrect e. Maternally inherited Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 Cinnabar eyes is a sex-linked recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes? Choose one answer. a. 50% Incorrect b. 100% Correct c. 0% Incorrect d. 25% Incorrect e. 75% Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Hydrophobic substances such as vegetable oil are Choose one answer. a. nonpolar substances that repel water molecules. Correct b. nonpolar substances that have an attraction for water molecules. Incorrect c. polar substances that have an affinity for water. Incorrect d. charged molecules that hydrogen-bond with water molecules. Incorrect e. polar substances that repel water molecules. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 At the summit of a high mountain, the atmospheric pressure is 380 mm Hg. If the atmosphere is still composed of 21% oxygen, what is the partial pressure of oxygen at this altitude? Choose one answer. a. 380 mm Hg Incorrect b. 0 mm Hg Incorrect c. 80 mm Hg Correct d. 160 mm Hg Incorrect e. 760 mm Hg Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 The ATP made during fermentation is generated by which of the following? Choose one answer. a. substrate-level phosphorylation Correct b. the electron transport chain Incorrect c. oxidative phosphorylation Incorrect d. chemiosmosis Incorrect e. aerobic respiration Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is hydrolyzed. Incorrect b. The excess is oxidized. Incorrect c. The excess is stored as glycogen. Correct d. The excess is eliminated. Incorrect e. The excess is stored as starch. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 If a pair of homologous chromosomes fails to separate during anaphase of meiosis I, what will be the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? Choose one answer. a. n + 1; n + 1; n; n Incorrect b. n + 1; n - 1; n; n Incorrect c. n + 1; n - 1; n - 1; n - 1 Incorrect d. n - 1; n - 1; n; n Incorrect e. n + 1; n + 1; n - 1; n - 1 Correct Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification? Choose one answer. a. The two forms have many genes in common. Incorrect b. The two forms are very similar in coloration. Incorrect c. The two forms have similar food requirements. Incorrect d. The two forms live in similar habitats. Incorrect e. The two forms interbreed often in nature, and their offspring have good survival and reproduction. Correct Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 In negative pressure breathing, inhalation results from Choose one answer. a. contracting the abdominal muscles. Incorrect b. forcing air from the throat down into the lungs. Incorrect c. contracting the diaphragm. Correct d. using muscles of the lungs to expand the alveoli. Incorrect e. relaxing the muscles of the rib cage. Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of Attempt 22 Started on Saturday, January 17, 2009, 10:39 AM Completed on Saturday, January 17, 2009, 10:39 AM Time taken 15 secs Raw score 0/60 (0%) Grade out of a maximum of Question 1 Marks: 1 Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs? Choose one answer. a. Water is less dense than air. Incorrect b. Gills have less surface area than lungs. Incorrect c. Gills allow water to flow in one direction Incorrect d. Water contains much less O2 than air per unit volume. Correct e. Gills allow only unidirectional transport Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Compared to the seawater around them, most marine invertebrates are Choose one answer. a. hyperosmotic and isoosmotic. Incorrect b. hyperosmotic. Incorrect c. hypoosmotic. Incorrect d. hypoosmotic and isoosmotic. Incorrect e. isoosmotic. Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, Choose one answer. a. mitochondria and peroxisomes. Incorrect b. peroxisomes and chloroplasts. Incorrect c. chloroplasts and mitochondria. Correct d. chloroplasts and peroxisomes. Incorrect e. mitochondria and chloroplasts. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following statements is true concerning catabolic pathways? Choose one answer. a. They are endergonic. Incorrect b. They build up complex molecules such as protein from simpler compounds. Incorrect c. They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. Correct d. They combine molecules into more energy-rich molecules. Incorrect e. They are spontaneous and do not need enzyme catalysis. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The volume of the thoracic cavity decreases. Correct b. The residual volume of the lungs decreases. Incorrect c. The epiglottis closes. Incorrect d. The diaphragm contracts. Incorrect e. The rib cage expands. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids? Choose one answer. a. 1220 Incorrect b. 125 Incorrect c. 2012 Correct d. 20 Incorrect e. 412 Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 One function of both alcohol fermentation and lactic acid fermentation is to Choose one answer. a. none of the above Incorrect b. oxidize NADH to NAD+. Correct c. reduce FADH2 to FAD+. Incorrect d. reduce NAD+ to NADH. Incorrect e. reduce FAD+ to FADH2. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 In thylakoids, protons travel through ATP synthase from the stroma to the thylakoid space. Therefore the catalytic "knobs" of ATP synthase would be located Choose one answer. a. on the side facing the thylakoid space. Incorrect b. built into the center of the thylkoid stack (granum). Incorrect c. on the pigment molecules of PSI and PSII. Incorrect d. on the stroma side of the membrane. Correct e. on the ATP molecules themselves. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The fish swam in a zig-zag motion. Correct b. The six pairs of robins hatched an average of three chicks. Incorrect c. The contents of the stomach are mixed every 20 seconds. Incorrect d. The plant's height is 25 centimeters (cm). Incorrect e. The temperature decreased from 20°C to 15°C. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? Choose one answer. a. energy released as electrons flow through the electron transport system Incorrect b. No external source of energy is required because the reaction is exergonic. Incorrect c. energy released from movement of protons through ATP synthase Correct d. energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix Incorrect e. energy released from substrate-level phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is measured by an electrocardiogram? Choose one answer. a. impulses of the parasympathetic nervous system that control heart beat Incorrect b. contraction of the two atria Incorrect c. the spread of impulses from the SA node Correct d. impulses from the AV node Incorrect e. systole and diastole Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)? Choose one answer. a. 16 Correct b. 2 Incorrect c. 8 Incorrect d. 32 Incorrect e. 4 Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis? Choose one answer. a. Disruption of one of these types of structure should necessarily disrupt each of the others as well. Incorrect b. Natural selection for motility must select for microtubular arrays in circular patterns. Correct c. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles. Incorrect d. Evolution of motility, of cells or of parts of cells, must have occurred only once. Incorrect e. Motor proteins such as dynein must have evolved before any of these four kinds of structure. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 If neutral variation is truly "neutral," then it should have no effect on Choose one answer. a. our ability to measure the rate of evolution. Incorrect b. gene diversity. Incorrect c. nucleotide diversity. Incorrect d. average heterozygosity. Incorrect e. relative fitness. Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis? Choose one answer. a. 100% Correct b. 0% Incorrect c. 10% Incorrect d. 38% Incorrect e. 2% Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light arebeing absorbed by this pigment? Choose one answer. a. green and yellow Incorrect b. red and yellow Incorrect c. green, blue, and yellow Incorrect d. blue, green, and red Incorrect e. blue and violet Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in Choose one answer. a. the release of water from sucrose as the bond between glucose and fructose is broken. Incorrect b. bringing glucose and fructose together to form sucrose. Incorrect c. breaking the bond between glucose and fructose and forming new bonds from the atoms of water. Correct d. utilization of water as a covalent bond is formed between glucose and fructose to form sucrase. Incorrect e. production of water from the sugar as bonds are broken between the glucose monomers. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which group possess excretory organs known as Malpighian tubules? Choose one answer. a. sea stars Incorrect b. insects Correct c. earthworms Incorrect d. jellyfish Incorrect e. flatworms Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. oxidative phosphorylation Incorrect b. the oxidation of pyruvate to acetyl CoA Incorrect c. glycolysis Correct d. chemiosmosis Incorrect e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur? Choose one answer. a. The reaction would change from endergonic to exergonic. Incorrect b. Nothing; the reaction would stay at equilibrium. Correct c. The free energy of the system would change. Incorrect d. Additional substrate would be formed. Incorrect e. Additional product would be formed. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Average blood pressure is lowest in which structure(s)? Choose one answer. a. arteries Incorrect b. venae cavae Correct c. the aorta Incorrect d. capillaries Incorrect e. arterioles Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which of the following statements is false for the class of biological molecules known as lipids? Choose one answer. a. They are soluble in water. Correct b. They contain waxes and steroids. Incorrect c. They are an important constituent of cell membranes. Incorrect d. They are not true polymers. Incorrect e. They contain more energy than proteins and carbohydrates. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Independent assortment of chromosomes occurs. Choose one answer. a. The statement is true for meiosis I only. Correct b. The statement is true for mitosis and meiosis II. Incorrect c. The statement is true for mitosis only. Incorrect d. The statement is true for mitosis and meiosis I. Incorrect e. The statement is true for meiosis II only. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Animals require certain amino acids in their diet. An amino acid that is referred to as nonessential would be best described as one that Choose one answer. a. must be ingested in the diet. Incorrect b. is less important than an essential amino acid. Incorrect c. is not used by the animal in biosynthesis. Incorrect d. is not found in many proteins. Incorrect e. can be made by the animal's body from other substances. Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it? Choose one answer. a. How can RNA molecules catalyze reactions? Incorrect b. How can amino acids, simple sugars, and nucleotides be synthesized abiotically? Incorrect c. How did RNA sequences come to carry the code for amino acid sequences? Correct d. How could polymers involving lipids and/or proteins form membranes in aqueous environments? Incorrect e. How can RNA molecules act as templates for the synthesis of complementary RNA molecules? Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Why are hydrocarbons insoluble in water? Choose one answer. a. The majority of their bonds are polar covalent carbon-to-hydrogen linkages. Incorrect b. They are lighter than water. Incorrect c. They exhibit considerable molecular complexity and diversity. Incorrect d. They are hydrophilic. Incorrect e. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. intestine Incorrect b. liver Incorrect c. pancreas Incorrect d. stomach Correct e. gallbladder Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which of the following triggers the cell's passage past the G2 checkpoint into mitosis? Choose one answer. a. Cdk Incorrect b. MPF Correct c. cyclin Incorrect d. PDGF Incorrect e. protein kinase Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? Choose one answer. a. Interphase Incorrect b. Telophase Incorrect c. Metaphase Correct d. Prophase Incorrect e. Anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Why are cattle able to survive on a diet consisting almost entirely of plant material? Choose one answer. a. Cattle saliva has enzymes capable of digesting cellulose. Incorrect b. They are autotrophic. Incorrect c. They manufacture all 15 amino acids out of sugars in the liver. Incorrect d. They have cellulose-digesting, symbiotic microorganisms in chambers of their stomachs. Correct e. Cattle, like the rabbit, reingest their feces. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 All of the following statements are part of Charles Darwin's concept of natural selection except Choose one answer. a. Every organism has the potential to produce more offspring than the local environment can support. Incorrect b. Most individuals in a species do not survive to reproduce. Incorrect c. Characteristics of organisms are inherited as genes on chromosomes. Correct d. Better adapted members of a species will survive and reproduce more successfully. Incorrect e. Slight inheritable variations within a population may make an individual significantly more or less likely to survive in its environment, and thus to reproduce. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following describe(s) cyclin-dependent kinase (Cdk)? Choose one answer. a. Both B and C are true. Correct b. Both A and B are true. Incorrect c. Cdk is an enzyme that attaches phosphate groups to other proteins. Incorrect d. Cdk is present throughout the cell cycle. Incorrect e. Cdk is inactive, or "turned off," in the presence of cyclin. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find? Choose one answer. a. There is no consistent relationship. Incorrect b. The pH of the stroma is higher than that of the other two measurements. Incorrect c. The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol. Incorrect d. The pH of the thylakoid space is higher than that anywhere else in the cell. Incorrect e. The pH within the thylakoid is less than that of the stroma. Correct Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which of the following vitamins is correctly associated with its use? Choose one answer. a. vitamin Aincorporated into the visual pigment of the eye Correct b. vitamin Dcalcium removal from bone Incorrect c. vitamin Eprotection of skin from cancer Incorrect d. vitamin Ccuring rickets Incorrect e. vitamin Kproduction of white blood cells Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 An important group of peripheral membrane proteins are enzymes, such as the phospholipases that attack the head groups of phospholipids leading to the degradation of damaged membranes. What properties must these enzymes exhibit? Choose one answer. a. membrane spanning domains Incorrect b. independence from cofactor interaction Incorrect c. lipid solubility Incorrect d. resistance to degradation Incorrect e. water solubility Correct Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Which process in the nephron is least selective? Choose one answer. a. secretion Incorrect b. filtration Correct c. salt pumping by the loop of Henle Incorrect d. active transport Incorrect e. reabsorption Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Most genes have many more than two alleles. However, which of the following is also true? Choose one answer. a. More than two alleles in a genotype is lethal. Incorrect b. All of the alleles but one will produce harmful effects if homozygous. Incorrect c. Most of the alleles will never be found in a live-born organism. Incorrect d. There may still be only two phenotypes for the trait. Correct e. At least one allele for a gene always produces a dominant phenotype. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which action could produce a carbonyl group? Choose one answer. a. the replacement of the OH of a carboxyl group with hydrogen Correct b. the addition of a thiol to a hydroxyl Incorrect c. the addition of a sulfhydryl to a carboxyl Incorrect d. the replacement of the nitrogen of an amine with oxygen Incorrect e. the addition of a hydroxyl to a phosphate Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Which of the following best demonstrates the unity among all organisms? Choose one answer. a. the structure and function of DNA Correct b. matching DNA nucleotide sequences Incorrect c. descent with modification Incorrect d. emergent properties Incorrect e. natural selection Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which feature of osmoregulation is found in both marine and freshwater bony fish? Choose one answer. a. loss of water in the urine Incorrect b. gain of water through food Correct c. gain of salt through the gills Incorrect d. loss of water through the gills Incorrect e. no drinking of water Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following contains its own DNA and ribosomes? Choose one answer. a. mitochondrion Correct b. peroxisome Incorrect c. Golgi apparatus Incorrect d. lysosome Incorrect e. vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Where does the Calvin cycle take place? Choose one answer. a. outer membrane of the chloroplast Incorrect b. stroma of the chloroplast Correct c. cytoplasm surrounding the chloroplast Incorrect d. thylakoid membrane Incorrect e. chlorophyll molecule Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. a bioinformatic system. Incorrect b. feedback inhibition. Incorrect c. negative feedback. Incorrect d. positive feedback. Correct e. enzymatic catalysis. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following features do all gas exchange systems have in common? Choose one answer. a. They are found only in animals. Incorrect b. The exchange surfaces are moist. Correct c. They are enclosed within ribs. Incorrect d. They are exposed to air. Incorrect e. They are maintained at a constant temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level? Choose one answer. a. ADP + Pi Incorrect b. ATP Incorrect c. NADH Incorrect d. FADH2 Correct e. NAD+ Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Who proposed that the membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids? Choose one answer. a. H. Davson and J. Danielli Incorrect b. C. Overton Incorrect c. S. Singer and G. Nicolson Correct d. E. Gorter and F. Grendel Incorrect e. I. Langmuir Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which branch of biology is concerned with the naming and classifying of organisms? Choose one answer. a. taxonomy Correct b. genomics Incorrect c. evolution Incorrect d. informatics Incorrect e. schematic biology Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 A number of systems for pumping across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Small increases in calcium ions in the cytosol trigger a number of different intracellular reactions, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10-7 in a resting cell, while the concentration in the SR can be 10-2, then how is the ATPase acting? Choose one answer. a. The calcium ions must be diffusing back into the SR along the concentration gradient. Incorrect b. The route of calcium ions must be from SR to the cytosol, to the cell's environment. Incorrect c. The ATP must be powering an inflow of calcium from the outside of the cell into the SR. Incorrect d. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. Correct e. ATP must be transferring Pi to the SR to enable this to occur. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 A couple has a child with Down syndrome when the mother is 39 years old at the time of delivery. Which is the most probable cause? Choose one answer. a. The woman inherited this tendency from her parents. Incorrect b. One member of the couple underwent nondisjunction in gamete production. Correct c. One member of the couple carried a translocation. Incorrect d. One member of the couple underwent nondisjunction in somatic cell production. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? Choose one answer. a. water the most, beer the least Incorrect b. beer the most, salt solution the least Correct c. beer the most, water the least Incorrect d. salt solution the most, water the least Incorrect e. There will be no significant difference between these groups. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 A hybrid zone is properly defined as Choose one answer. a. an area where members of two closely related species intermingle, but experience no gene flow. Incorrect b. an area where mating occurs between members of two closely related species, producing viable offspring. Correct c. a zone that features a gradual change in species composition where two neighboring ecosystems border each other. Incorrect d. a zone that includes the intermediate portion of a cline. Incorrect e. an area where two closely related species' ranges overlap. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. a. carbon dioxide is incorporated into PGA. Incorrect b. NADP is produced. Incorrect c. NADPH is reduced to NADP+. Incorrect d. light is absorbed and funneled to reaction-center chlorophyll a. Correct e. ATP is phosphorylated to yield ADP. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 In which of the following would you expect to find an enlarged cecum? Choose one answer. a. rabbits, horses, and herbivorous bears Correct b. carnivorous animals Incorrect c. humans and other primates Incorrect d. tapeworms and other intestinal parasites Incorrect e. tubeworms that digest via symbionts Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 In order for chromosomes to undergo inversion or translocation, which of the following is required? Choose one answer. a. Advanced maternal age Incorrect b. Point mutation Incorrect c. Meiosis Incorrect d. Immunological insufficiency Incorrect e. Chromosome breakage and rejoining Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 What is generally true of two very closely related species that have diverged from each other quite recently? Choose one answer. a. Genes are unable to pass from one species' gene pool to the other's gene pool. Incorrect b. They are unable to produce hybrid offspring upon interbreeding. Incorrect c. Their reproductive isolation from each other is complete. Incorrect d. They shared a common ancestor recently in evolutionary time. Correct Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Down syndrome has a frequency in the U.S. population of ~ 1/700 live births. In which of the following groups would you expect this to be significantly higher? Choose one answer. a. People in Latin or South America Incorrect b. The Inuit and other peoples in very cold habitats Incorrect c. No groups have such higher frequency Correct d. People living in equatorial areas of the world Incorrect e. Very small population groups Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct b. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect c. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect d. It may explain the transmission of Duchenne muscular dystrophy. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 Which of these is a statement that Darwin would have rejected? Choose one answer. a. The smallest entity that can evolve is an individual organism. Correct b. Environmental change plays a role in evolution. Incorrect c. Inherited variation in a population is a necessary precondition for natural selection to operate. Incorrect d. Individuals can acquire new characteristics as they respond to new environments or situations. Incorrect e. Natural populations tend to produce more offspring than the environment can support. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 The mitochondrion, like the nucleus, has two or more membrane layers. How is the innermost of these layers different from that of the nucleus? Choose one answer. a. The inner mitochondrial membrane is highly folded. Correct b. The inner membrane of the mitochondrion is separated out into thylakoids. Incorrect c. The two membranes are biochemically very different. Incorrect d. The space between the two layers of the nuclear membrane is larger. Incorrect e. The inner mitochondrial membrane is devoid of nearly all proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 How many grams of acetic acid (C2H4O2) would you use to make 10 L of a 0.1 M aqueous solution of acetic acid? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) Choose one answer. a. 6.0 g Incorrect b. 10.0 g Incorrect c. 0.1 g Incorrect d. 60.0 g Correct e. 0.6 g Incorrect Incorrect Marks for this submission: 0/1. Time Remaining 9 Weeks Exam Practice Review of attempt 11 Started on Saturday, 17 January 2009, 11:36 AM Completed on Saturday, 17 January 2009, 11:36 AM Time taken 10 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 The human X and Y chromosomes Choose one answer. a. are of approximately equal size and number of genes. Incorrect b. include only genes that govern sex determination. Incorrect c. are both present in every somatic cell of males and females alike. Incorrect d. are almost entirely homologous, despite their different names. Incorrect e. include genes that determine an individual's sex. Correct Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Life is diverse. How many species are estimated to be presently on the earth? Choose one answer. a. 1,800 Incorrect b. 180,000,000 Incorrect c. 180,000 Incorrect d. 1,800,000 Correct e. 18,000,000 Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 A freshwater fish was accidentally placed in salt water. After several minutes in this saline water, it died. What is the most logical explanation for its death? Choose one answer. a. Brain cells lysed as a result of increased osmotic pressure in this hyperosmotic environment; death by loss of autonomic function. Incorrect b. Loss of water by osmosis in cells in vital organs resulting in cell death and eventually organ failure. Correct c. The gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation. Incorrect d. Salt diffused into all the fish's cells causing them to swell and, in some cases, lyse. Incorrect e. The kidneys were not able to keep up with the water removal necessary in this hyperosmotic environment creating an irrevocable loss of homeostasis. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Experiments with cohesions have found that Choose one answer. a. a protein that cleaves cohesions would cause cellular death. Incorrect b. cohesions are protected from cleavage at the centromere during meiosis I. Correct c. a protein cleaves cohesions before metaphase I. Incorrect d. cohesions are cleaved from chromosomes at the centromere before anaphase I. Incorrect e. cohesions are protected from destruction throughout meiosis I and II. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 What is the change in free energy of a system at chemical equilibrium? Choose one answer. a. greatly increasing Incorrect b. slightly decreasing Incorrect c. no net change Correct d. slightly increasing Incorrect e. greatly decreasing Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Chromosomes first become visible during which phase of mitosis? Choose one answer. a. anaphase Incorrect b. prometaphase Incorrect c. prophase Correct d. metaphase Incorrect e. telophase Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 At what temperature is water at its densest? Choose one answer. a. 212°C Incorrect b. 100°C Incorrect c. 0°C Incorrect d. 4°C Correct e. 32°C Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into Choose one answer. a. the energy of motion. Incorrect b. carbon dioxide and water. Incorrect c. oxygen. Incorrect d. the potential energy of chemical bonds. Correct e. kinetic energy. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following hormone actions will occur when more energy is required by a human? Choose one answer. a. Both insulin and glucagon decrease. Incorrect b. Blood insulin increases. Incorrect c. Blood glucagon increases. Correct d. Thyroid hormone is increased. Incorrect e. Both insulin and glucagon increase. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Which of the following features do all gas exchange systems have in common? Choose one answer. a. They are maintained at a constant temperature. Incorrect b. They are found only in animals. Incorrect c. They are enclosed within ribs. Incorrect d. The exchange surfaces are moist. Correct e. They are exposed to air. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. tonoplast → primary cell wall → plasma membrane → cytoplasm Incorrect b. plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect c. secondary cell wall → plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect d. primary cell wall → plasma membrane → cytoplasm → tonoplast Correct e. primary cell wall → plasma membrane → tonoplast → cytoplasm → vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells? Choose one answer. a. Blood pH will decrease slightly. Correct b. Blood pH will remain unchanged. Incorrect c. Blood pH will first decrease, then increase sharply as CO2 combines with hemoglobin. Incorrect d. Blood pH will increase slightly. Incorrect e. Blood pH will first increase, then decrease as CO2 combines with hemoglobin. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following is true of enzymes? Choose one answer. a. Enzymes may require a nonprotein cofactor or ion for catalysis to take speed up more appreciably than if the enzymes act alone. Incorrect b. Enzyme function is increased if the three-dimensional structure or conformation of an enzyme is altered. Incorrect c. Enzymes increase the rate of chemical reaction by lowering activation energy barriers. Correct d. Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 What is the reason that linked genes are inherited together? Choose one answer. a. They are located close together on the same chromosome. Correct b. Genes align that way during metaphase I of meiosis. Incorrect 9 Weeks Exam Practice Review of attempt 12 Started on Saturday, 17 January 2009, 11:37 AM Completed on Saturday, 17 January 2009, 11:38 AM Time taken 12 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 Materials are returned to the blood from the filtrate by which of the following processes? Choose one answer. a. filtration Incorrect b. secretion Incorrect c. active transport Incorrect d. selective reabsorption Correct e. ultrafiltration Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 A cell divides to produce two daughter cells that are genetically different. Choose one answer. a. The statement is true for meiosis I only. Correct b. The statement is true for mitosis and meiosis I. Incorrect c. The statement is true for mitosis only. Incorrect d. The statement is true for meiosis II only. Incorrect e. The statement is true for mitosis and meiosis II. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? Choose one answer. a. XcXc and XcY Incorrect b. XCXC and XcY Incorrect c. XCXC and XCY Incorrect d. XCXcand XCY Correct e. XcXcand XCY Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population? Choose one answer. a. No selection would operate because the population is in Hardy-Weinberg equilibrium. Incorrect b. stabilizing selection Incorrect c. sexual selection Incorrect d. directional selection Correct e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following metabolic processes can occur without a net influx of energy from some other process? Choose one answer. a. ADP + Pi → ATP + H2O Incorrect b. amino acids → protein Incorrect c. glucose + fructose → sucrose Incorrect d. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 Incorrect e. C6H12O6 + 6 O2 → 6 CO2 + 6H2O Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? Choose one answer. a. competitive inhibition Correct b. saturation of the enzyme activity Incorrect c. allosteric inhibition Incorrect d. insufficient cofactors Incorrect e. denaturization of the enzyme Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. distal tubules Correct b. collecting duct Incorrect c. loop of Henle Incorrect d. Bowman's capsule Incorrect e. proximal tubule Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of the following occurs in the cytosol of a eukaryotic cell? Choose one answer. a. fermentation and chemiosmosis Incorrect b. citric acid cycle Incorrect c. oxidation of pyruvate to acetyl CoA Incorrect d. glycolysis and fermentation Correct e. oxidative phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It may explain the transmission of Duchenne muscular dystrophy. Incorrect b. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect c. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct d. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 In order for a protein to be an integral membrane protein it would have to be which of the following? Choose one answer. a. hydrophilic Incorrect b. completely covered with phospholipids Incorrect c. exposed on only one surface of the membrane Incorrect d. hydrophobic Incorrect e. amphipathic Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Where and from what compound(s) is urea produced? Choose one answer. a. bladder from uric acid and H2O Incorrect b. liver from glycogen Incorrect c. liver from NH3 and CO2 Correct d. kidneys from glycerol and fatty acids Incorrect e. kidneys from glucose Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Evolution is biology's core theme that ties together all the other themes. This is because evolution explains Choose one answer. a. explains why some organisms have traits in common. Incorrect b. how organisms become adapted to their environment through the differential reproductive success of varying individuals. Incorrect c. the unity and diversity of life. Incorrect d. all of the above Correct e. why distantly related organisms sometimes resemble each other. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following animals is incorrectly paired with its feeding mechanism? Choose one answer. a. aphidfluid feeder Incorrect b. clamsuspension feeder Incorrect c. baleen whalesuspension feeder Incorrect d. snakebulk feeder Incorrect e. lionsubstrate feeder Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 The light reactions of photosynthesis supply the Calvin cycle with Choose one answer. a. CO2 and ATP. Incorrect b. light energy. Incorrect c. ATP and NADPH. Correct d. sugar and O2. Incorrect e. H2O and NADPH. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following statements is true of mammals? Choose one answer. a. Enzyme production continues in the esophagus. Incorrect b. After leaving the oral cavity, the bolus enters the larynx. Incorrect c. All foods begin their enzymatic digestion in the mouth. Incorrect d. The trachea leads to the esophagus and then to the stomach. Incorrect e. The epiglottis prevents food from entering the trachea. Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 A solution contains 0.0000001(10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution? Choose one answer. a. neutral Correct b. basic: H+ acceptor Incorrect c. basic: H+ donor Incorrect d. acidic: H+ acceptor Incorrect e. acidic: H+ donor Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? Choose one answer. a. Forelimb evolution was adaptive in people and bats, but not in whales. Incorrect b. Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. Incorrect c. Whales are not properly classified as mammals. Incorrect d. Genes mutate faster in whales than in humans or bats. Incorrect e. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from Choose one answer. a. an animal, but not a plant. Incorrect b. any kind of organism. Incorrect c. a plant, but not an animal. Incorrect d. a bacterium. Incorrect e. a plant or an animal. Correct Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following occurs when digestion of organic molecules results in more energy-rich molecules than are immediately required by the animal? Choose one answer. a. The excess is hydrolyzed. Incorrect b. The excess is stored as starch. Incorrect c. The excess is oxidized. Incorrect d. The excess is stored as glycogen. Correct e. The excess is eliminated. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 What are the products of the light reactions that are subsequently used by the Calvin cycle? Choose one answer. a. oxygen and carbon dioxide Incorrect b. water and carbon Incorrect c. ATP and NADPH Correct d. carbon dioxide and RuBP Incorrect e. electrons and photons Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide would be found within the Choose one answer. a. ribosomes. Incorrect b. peroxisomes. Incorrect c. endoplasmic reticulum. Incorrect d. lysosomes. Incorrect e. mitochondria. Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Most cells cannot harness heat to perform work because Choose one answer. a. temperature is usually uniform throughout a cell. Correct b. heat denatures enzymes. Incorrect c. heat is not a form of energy. Incorrect d. cells do not have much heat; they are relatively cool. Incorrect e. heat can never be used to do work. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? Choose one answer. a. the splitting of water Incorrect b. the synthesis of ATP Correct c. the reduction of NADP+ Incorrect d. the flow of electrons from photosystem II to photosystem I Incorrect e. the absorption of light energy by chlorophyll Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence? Choose one answer. a. Gene flow Incorrect b. Non-random mating Incorrect c. Mutation Incorrect d. Natural selection Incorrect e. Genetic drift Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. a. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct b. Theories are hypotheses that have been proved. Incorrect c. Hypotheses are guesses; theories are correct answers. Incorrect d. Theories are proved true in all cases; hypotheses are usually falsified by tests. Incorrect e. Hypotheses and theories are essentially the same thing. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 In what way do the membranes of a eukaryotic cell vary? Choose one answer. a. Certain proteins are unique to each membrane. Correct b. Only certain membranes are constructed from amphipathic molecules. Incorrect c. Phospholipids are found only in certain membranes. Incorrect d. Only certain membranes of the cell are selectively permeable. Incorrect e. Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.) Choose one answer. a. 100°C Incorrect b. 50°C Incorrect c. 10°C Correct d. 1°C Incorrect e. 5°C Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of Choose one answer. a. a snowball Earth. Incorrect b. the delivery of organic matter to Earth by meteors and comets. Incorrect c. the abiotic synthesis of organic monomers. Incorrect d. earlier genetic systems than those based on DNA. Correct e. the endosymbiotic origin of mitochondria and chloroplasts. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Pure, freshly-distilled water has a pH of 7. This means that Choose one answer. a. there are no OH- ions in the water. Incorrect b. The concentration of OH- ions in the water is 7 times the concentration of H+ ions in the water. Incorrect c. the concentration of H+ ions in the water is 7 times the concentration of OH- ions in the water. Incorrect d. there are no H+ ions in the water. Incorrect e. the concentration of H+ ions in the water equals the concentration of OH- ions in the water. Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? Choose one answer. a. the release of heat by the formation of hydrogen bonds Incorrect b. the absorption of heat by the breaking of hydrogen bonds Correct c. water's ability to dissolve molecules in the air Incorrect d. water's change in density when it condenses Incorrect e. water's high surface tension Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart? Choose one answer. a. fishes Correct b. amphibians Incorrect c. birds Incorrect d. reptiles Incorrect e. mammals Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 What is a chromatid? Choose one answer. a. a chromosome in G1 of the cell cycle Incorrect b. a special region that holds two centromeres together Incorrect c. another name for the chromosomes found in genetics Incorrect d. a chromosome found outside the nucleus Incorrect e. a replicate chromosome Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 What is the purpose of beta oxidation in respiration? Choose one answer. a. breakdown of fatty acids Correct b. control of ATP accumulation Incorrect c. feedback regulation Incorrect d. oxidation of glucose Incorrect e. oxidation of pyruvate Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Bacteria are beneficial to animal nutrition, including that of humans. Which of the following is among their greatest benefits to us? Choose one answer. a. production of vitamins A and C Incorrect b. generation of gases needed for elimination Incorrect c. absorption of organic materials Incorrect d. production of biotin and vitamin K Correct e. recovery of water from fecal matter Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 You have a friend who lost 7 kg (about 15 pounds) of fat on a "low carb" diet. How did the fat leave her body? Choose one answer. a. It was released as CO2 and H2O. Correct b. It was converted to urine and eliminated from the body. Incorrect c. Chemical energy was converted to heat and then released. Incorrect d. It was converted to ATP, which weighs much less than fat. Incorrect e. It was broken down to amino acids and eliminated from the body. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The sugar that results from three "turns" of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this? Choose one answer. a. The formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements. Correct b. G3P more readily forms sucrose and other disaccharides than it does monosaccharides. Incorrect c. Some plants would not taste sweet to us. Incorrect d. G3P is easier for a plant to store. Incorrect e. Formation of a molecule of glucose would require 9 "turns." Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which of the following processes of osmoregulation by the kidney is the least selective? Choose one answer. a. H+ pumping to control pH Incorrect b. secretion Incorrect c. filtration Correct d. reabsorption Incorrect e. salt pumping to control osmolarity Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The blood level of which gas is most important in controlling human respiration rate? Choose one answer. a. nitrogen Incorrect b. oxygen Incorrect c. carbon monoxide Incorrect d. nitric acid Incorrect e. carbon dioxide Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 In animals, nitrogenous wastes are produced mostly from the catabolism of Choose one answer. a. phospholipids and glycolipids. Incorrect b. proteins and nucleic acids. Correct c. starch and cellulose. Incorrect d. fatty acids and glycerol. Incorrect e. triglycerides and steroids. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. mollusc Incorrect b. fish Incorrect c. annelid Incorrect d. frog Correct e. insect Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule? Choose one answer. a. reduction of pyruvate to lactate Incorrect b. the electron transport chain Incorrect c. the citric acid cycle Incorrect d. synthesis of acetyl CoA from pyruvate Incorrect e. glycolysis Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways? Choose one answer. a. cooperativity Incorrect b. feedback regulation Incorrect c. bioenergetics Incorrect d. entropy Incorrect e. energy coupling Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following is a false statement regarding deoxyribonucleic acid (DNA)? Choose one answer. a. DNA is composed of chemical building blocks called nucleotides. Incorrect b. DNA is a code for the sequence of amino acids in a protein. Incorrect c. Genes are composed of deoxyribonucleic acid. Incorrect d. Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. Incorrect e. DNA is an enzyme that puts together amino acids to make a protein. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following minerals is associated with its use in animals? Choose one answer. a. iodineimportant in nerve function Incorrect b. magnesiumcofactor in enzymes that make ATP Incorrect c. ironnecessary for thyroid function Incorrect d. calciumconstruction and maintenance of bone Correct e. sulfuringredient of nucleic acids Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Reduction of NADP+ occurs during Choose one answer. a. photorespiration. Incorrect b. both photosynthesis and respiration. Incorrect c. neither photosynthesis nor respiration. Incorrect d. respiration. Incorrect e. photosynthesis. Correct Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 There are 40 individuals in population 1, all of which have genotype A1A1, and there are 25 individuals in population 2, all of genotype A2A2. Assume that these populations are located far from one another and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is mostly likely an example of Choose one answer. a. disruptive selection. Incorrect b. directional selection. Incorrect c. gene flow. Incorrect d. genetic drift. Correct e. discrete variation. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following is true of both starch and cellulose? Choose one answer. a. They are both polymers of glucose. Correct b. They are both structural components of the plant cell wall. Incorrect c. They are both used for energy storage in plants. Incorrect d. They can both be digested by humans. Incorrect e. They are geometric isomers of each other. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a[[no]] Choose one answer. a. two-chambered heart. Incorrect b. lymphatic system. Incorrect c. four-chambered heart. Correct d. open circulatory system. Incorrect e. hemocoel. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect b. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect c. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct d. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect e. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 How can one increase the rate of a chemical reaction? Choose one answer. a. Increase the activation energy needed. Incorrect b. Add a catalyst. Correct c. Increase the entropy of the reactants. Incorrect d. Decrease the concentration of the reactants. Incorrect e. Cool the reactants. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Nerve and muscle cells are in this phase: Choose one answer. a. G2 Incorrect b. M Incorrect c. G1 Incorrect d. S Incorrect e. G0 Correct Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 The lowest level of biological organization that can perform all the activities required for life is the Choose one answer. a. tissue–for example, nervous tissue. Incorrect b. organelle–for example, a chloroplast. Incorrect c. organism–for example, an amoeba, dog, human, or maple tree. Incorrect d. cell–for example, a skin cell. Correct e. organ system–for example, the reproductive system. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 During cellular respiration, acetyl CoA accumulates in which location? Choose one answer. a. cytosol Incorrect b. mitochondrial intermembrane space Incorrect c. mitochondrial inner membrane Incorrect d. mitochondrial matrix Correct e. mitochondrial outer membrane Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this? Choose one answer. a. Incomplete dominance Incorrect b. Multiple alleles Incorrect c. Pleiotropy Correct d. Epistasis Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 A gene's location along a chromosome is known as which of the following? Choose one answer. a. Variant Incorrect b. Locus Correct c. Sequence Incorrect d. Allele Incorrect e. Trait Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Abnormal chromosomes are frequent in malignant tumors. Errors such as translocations may place a gene in close proximity to different control regions. Which of the following might then occur to make the cancer worse? Choose one answer. a. A decrease in mitotic frequency Incorrect b. Sensitivity of the immune system Incorrect c. Death of the cancer cells in the tumor Incorrect d. Expression of inappropriate gene products Correct e. An increase in non-disjunction Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Familial hypercholesterolemia is characterized by which of the following? Choose one answer. a. inhibition of the cholesterol active transport system in red blood cells Incorrect b. a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes Incorrect c. a general lack of glycolipids in the blood cell membranes Incorrect d. poor attachment of the cholesterol to the extracellular matrix of cells Incorrect e. defective LDL receptors on the cell membranes Correct Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 DNA is replicated at this time of the cell cycle: Choose one answer. a. M Incorrect b. G1 Incorrect c. G2 Incorrect d. S Correct e. G0 Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 9 Weeks Exam Practice Review of attempt 13 Started on Saturday, 17 January 2009, 11:38 AM Completed on Saturday, 17 January 2009, 11:38 AM Time taken 7 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 Which chemical group is most likely to be responsible for an organic molecule behaving as a base? Choose one answer. a. carbonyl Incorrect b. phosphate Incorrect c. amino Correct d. carboxyl Incorrect e. hydroxyl Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Evolution is biology's core theme that ties together all the other themes. This is because evolution explains Choose one answer. a. how organisms become adapted to their environment through the differential reproductive success of varying individuals. Incorrect b. the unity and diversity of life. Incorrect c. why distantly related organisms sometimes resemble each other. Incorrect d. all of the above Correct e. explains why some organisms have traits in common. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of these is a statement that Darwin would have rejected? Choose one answer. a. Natural populations tend to produce more offspring than the environment can support. Incorrect b. Environmental change plays a role in evolution. Incorrect c. Inherited variation in a population is a necessary precondition for natural selection to operate. Incorrect d. Individuals can acquire new characteristics as they respond to new environments or situations. Incorrect e. The smallest entity that can evolve is an individual organism. Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Large proteins such as albumin remain in capillaries rather than diffusing out. Which of the following does this cause? Choose one answer. a. loss of osmotic pressure in the capillaries Incorrect b. increased diffusion of Hb Incorrect c. increased diffusion of CO2 Incorrect d. creation of an osmotic pressure difference across capillary walls Correct e. loss of fluid from capillaries Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? Choose one answer. a. 8 Incorrect b. 4 Incorrect c. 32 Correct d. 16 Incorrect e. 64 Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a Choose one answer. a. C3 plant. Incorrect b. C4 plant. Correct c. chemoautotroph. Incorrect d. heterotroph. Incorrect e. CAM plant. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? Choose one answer. a. K+ Incorrect b. glucose Incorrect c. starch Incorrect d. an amino acid Incorrect e. CO2 Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to sea water. They are therefore considered by many to be osmoconformers because of the unusual way they maintain homeostasis. They osmoregulate by Choose one answer. a. tolerating high urea concentrations that balance internal salt concentrations to sea water osmolarity. Correct b. using their gills and kidneys to rid themselves of sea salts. Incorrect c. monitoring dehydration at the cellular level with special gated aquaporins. Incorrect d. possessing a special adaptation that allows their cells to operate at an unusually high salt concentration. Incorrect e. synthesizing trimethylamine oxide, a chemical that speeds salt removal from cells. Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy? Choose one answer. a. Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O). Correct b. The electrons have a higher potential energy when associated with water and CO2 than they do in organic compounds. Incorrect c. The oxidation of organic compounds can be used to make ATP. Incorrect d. The covalent bond in O2 is unstable and easily broken by electrons from organic molecules. Incorrect e. The covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism Choose one answer. a. mates more frequently than others of its species. Incorrect b. utilizes resources more efficiently than other species occupying similar niches. Incorrect c. competes for resources more successfully than others of its species. Incorrect d. leaves more viable offspring than others of its species. Correct e. lives longer than others of its species. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Competitive inhibitors block the entry of substrate into the active site of an enzyme. On which of the following properties of an active site does this primarily depend? Choose one answer. a. the enzyme providing an appropriate microenvironment conducive to a reaction's occurrence Incorrect b. the ability of an enzyme to form a template for holding and joining molecules Correct c. the enzyme forming covalent bonds with the reactants Incorrect d. the enzyme's ability to stretch reactants and move them toward a transition state Incorrect e. the enzyme becoming too saturated because of the concentration of substrate Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? Choose one answer. a. eating a pizza with olives and pepperoni Incorrect b. sleeping Incorrect c. eating a bag of potato chips Incorrect d. drinking several glasses of water Incorrect e. spending several hours mowing the lawn on a hot day Correct Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. blood proteins Incorrect b. muscle and liver glycogen Correct c. muscle proteins Incorrect d. fat stored in adipose tissue Incorrect e. fat stored in the liver Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 How is most of the carbon dioxide transported by the blood in humans? Choose one answer. a. carbonic acid in the erythrocytes Incorrect b. bicarbonate ions in the plasma Correct c. CO2 dissolved in the plasma Incorrect d. bicarbonate attached to hemoglobin Incorrect e. CO2 attached to hemoglobin Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility, and death, usually of coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption? Choose one answer. a. Each patient will have had at least one affected family member in a previous generation. Incorrect b. All cases must occur in relatives; therefore, there must be only one mutant allele. Incorrect c. The disease is autosomal dominant. Incorrect d. The disorder may be due to mutation in a single protein-coding gene. Correct e. Successive generations of a family will continue to have more and more cases over time. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of these provides evidence of the common ancestry of all life? Choose one answer. a. the structure of cilia Incorrect b. the universality of the genetic code Correct c. the structure of chloroplasts Incorrect d. the ubiquitous use of catalysts by living systems Incorrect e. the structure of the nucleus Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following statements best describes the relationship between photosynthesis and respiration? Choose one answer. a. ATP molecules are produced in photosynthesis and used up in respiration. Incorrect b. Respiration is anabolic and photosynthesis is catabolic. Incorrect c. Photosynthesis stores energy in complex organic molecules, while respiration releases it. Correct d. Photosynthesis occurs only in plants and respiration occurs only in animals. Incorrect e. Respiration is the reversal of the biochemical pathways of photosynthesis. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect b. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct c. There is no possibility of having chemical equilibrium in any living cell. Incorrect d. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect e. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 PKU (phenylketonuria) is a hereditary condition in which infants and young children cannot ingest any more than tiny amounts of the amino acid phenylalanine without serious neurological results. This damage can be prevented by a severe restriction of phenylalanine in the diet. Which of the following is the nutritional concept that forms the basis for this preventive treatment? Choose one answer. a. symbiosis Incorrect b. dehydration synthesis Incorrect c. essential nutrients Correct d. enzymatic hydrolysis Incorrect e. structural anatomy of the brain Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 This is the shortest part of the cell cycle: Choose one answer. a. M Correct b. S Incorrect c. G0 Incorrect d. G1 Incorrect e. G2 Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as Choose one answer. a. feedback inhibition. Correct b. noncooperative inhibition. Incorrect c. allosteric inhibition. Incorrect d. metabolic inhibition. Incorrect e. reversible inhibition. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 What part(s) of the digestive system have secretions with a pH of 2? Choose one answer. a. stomach Correct b. small intestine Incorrect c. mouth Incorrect d. pancreas Incorrect e. liver Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Organic chemistry is a science based on the study of Choose one answer. a. water and its interaction with other kinds of molecules. Incorrect b. functional groups. Incorrect c. vital forces interacting with matter. Incorrect d. inorganic compounds. Incorrect e. carbon compounds. Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Why is the velocity of blood flow the lowest in capillaries? Choose one answer. a. The capillary walls are not thin enough to allow oxygen to exchange with the cells. Incorrect b. The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. Incorrect c. The total surface area of the capillaries is larger than the total surface area of the arterioles. Correct d. The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle. Incorrect e. Capillaries are far from the heart, and blood flow slows as distance from the heart increases. Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following is true of a species that has a chromosome number of 2n = 16? Choose one answer. a. During the S phase of the cell cycle there will be 32 separate chromosomes. Incorrect b. Each cell has 8 homologous pairs. Correct c. A gamete from this species has 4 chromosomes. Incorrect d. The species is diploid with 32 chromosomes per cell. Incorrect e. The species has 16 sets of chromosomes per cell. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 What is a karyotype? Choose one answer. a. A system of classifying cell nuclei Incorrect b. The set of unique physical characteristics that define an individual Incorrect c. A display of every pair of homologous chromosomes within a cell, organized according to size and shape Correct d. The combination of chromosomes found in a gamete Incorrect e. The collection of all the mutations present within the genome of an individual Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? Choose one answer. a. The cells of the sea star dehydrated and lost the ability to metabolize. Incorrect b. The contractile vacuoles used to regulate water content ruptured in the freshwater. Incorrect c. The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. Incorrect d. The sea star is hyperosmotic to the freshwater, and it could not osmoregulate. Correct e. The sea star was stressed and needed more time to acclimate to new conditions. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 What is the voltage across a membrane called? Choose one answer. a. water potential Incorrect b. electrochemical gradient Incorrect c. chemical gradient Incorrect d. osmotic potential Incorrect e. membrane potential Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? Choose one answer. a. 6 Incorrect b. 8 Incorrect c. 10 Incorrect d. 2 Correct e. 4 Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the following statements concerning unsaturated fats is true? Choose one answer. a. They are more common in animals than in plants. Incorrect b. They have fewer fatty acid molecules per fat molecule. Incorrect c. They have double bonds in the carbon chains of their fatty acids. Correct d. They contain more hydrogen than saturated fats having the same number of carbon atoms. Incorrect e. They generally solidify at room temperature. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by Choose one answer. a. van der Waals interactions. Incorrect b. ionic bonds. Incorrect c. polar covalent bonds. Correct d. nonpolar covalent bonds. Incorrect e. hydrogen bonds. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 The mammalian trachea and esophagus both connect to the Choose one answer. a. rectum. Incorrect b. stomach. Incorrect c. epiglottis. Incorrect d. large intestine. Incorrect e. pharynx. Correct Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 A number of systems for pumping across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Small increases in calcium ions in the cytosol trigger a number of different intracellular reactions, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10-7 in a resting cell, while the concentration in the SR can be 10-2, then how is the ATPase acting? Choose one answer. a. The route of calcium ions must be from SR to the cytosol, to the cell's environment. Incorrect b. The ATP must be powering an inflow of calcium from the outside of the cell into the SR. Incorrect c. The calcium ions must be diffusing back into the SR along the concentration gradient. Incorrect d. ATP must be transferring Pi to the SR to enable this to occur. Incorrect e. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. Correct Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. oxidative phosphorylation Incorrect b. the oxidation of pyruvate to acetyl CoA Incorrect c. chemiosmosis Incorrect d. glycolysis Correct e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely true? Choose one answer. a. Glucose is entering the cell along its concentration gradient. Incorrect b. A substance that blocked sodium ions from binding to the cotransport protein would also block the transport of glucose. Correct c. The sodium ions are moving down their electrochemical gradient while glucose is moving up. Incorrect d. Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. Incorrect e. Potassium ions move across the same gradient as sodium ions. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Choose one answer. a. glycolysis and the oxidation of pyruvate to acetyl CoA Incorrect b. oxidative phosphorylation and fermentation Incorrect c. fermentation and glycolysis Incorrect d. oxidation of pyruvate to acetyl CoA and the citric acid cycle Correct e. the citric acid cycle and oxidative phosphorylation Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? Choose one answer. a. a mouse species living in a temperate broadleaf forest Incorrect b. a beaver Incorrect c. a mouse species living in a tropical rain forest Incorrect d. a mouse species living in the desert Correct e. a river otter Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following contains its own DNA and ribosomes? Choose one answer. a. mitochondrion Correct b. peroxisome Incorrect c. lysosome Incorrect d. vacuole Incorrect e. Golgi apparatus Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Tallness (T) in snapdragons is dominant to dwarfness (t), while red (R) flower color is dominant to white (r). The heterozygous condition results in pink (Rr) flower color. A dwarf, red snapdragon is crossed with a plant homozygous for tallness and white flowers. What are the genotype and phenotype of the F1 individuals? Choose one answer. a. ttRr–dwarf and pink Incorrect b. ttrr–dwarf and white Incorrect c. TtRr–tall and red Incorrect d. TtRr–tall and pink Correct e. TTRR–tall and red Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Which of the following is a normal event in the process of blood clotting? Choose one answer. a. conversion of fibrin to fibrinogen Incorrect b. production of erythropoietin Incorrect c. clotting factor formation Incorrect d. activation of prothrombin to thrombin Correct e. increase in platelets Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to which of the following as a probable hypothesis? Choose one answer. a. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles. Incorrect b. Evolution of motility, of cells or of parts of cells, must have occurred only once. Incorrect c. Disruption of one of these types of structure should necessarily disrupt each of the others as well. Incorrect d. Natural selection for motility must select for microtubular arrays in circular patterns. Correct e. Motor proteins such as dynein must have evolved before any of these four kinds of structure. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Natural selection is based on all of the following except Choose one answer. a. populations tend to produce more individuals than the environment can support. Incorrect b. individuals adapt to their environments and, thereby, evolve. Correct c. individuals who survive longer tend to leave more offspring than those who die young. Incorrect d. genetic variation exists within populations. Incorrect e. the best-adapted individuals tend to leave the most offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. a. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct b. Theories are hypotheses that have been proved. Incorrect c. Hypotheses are guesses; theories are correct answers. Incorrect d. Hypotheses and theories are essentially the same thing. Incorrect e. Theories are proved true in all cases; hypotheses are usually falsified by tests. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Processing of filtrate in the proximal and distal tubules accomplishes what important function? Choose one answer. a. converting toxic ammonia to less toxic urea Incorrect b. maintaining a constant pH in body fluids Correct c. sorting plasma proteins according to size Incorrect d. regulating the speed of blood flow through the nephron Incorrect e. reabsorbing urea to maintain osmotic balance Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 The application of scientific knowledge for some specific purpose is known as Choose one answer. a. deductive science. Incorrect b. pure science. Incorrect c. technology. Correct d. inductive science. Incorrect e. anthropologic science. Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? Choose one answer. a. 4:3 male to female Incorrect b. 1:2 male to female Incorrect c. 2:1 male to female Correct d. 3:1 male to female Incorrect e. 1:1 male to female Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 What does a frequency of recombination of 50% indicate? Choose one answer. a. The two genes are likely to be located on different chromosomes. Correct b. The genes are located on sex chromosomes. Incorrect c. Independent assortment is hindered. Incorrect d. Abnormal meiosis has occurred. Incorrect e. All of the offspring have combinations of traits that match one of the two parents. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive): 1. Natural selection 2. Microevolution 3. Intrasexual selection 4. Evolution 5. Sexual selection Choose one answer. a. 4, 1, 2, 3, 5 Incorrect b. 4, 2, 1, 5, 3 Correct c. 1, 2, 4, 5, 3 Incorrect d. 4, 2, 1, 3, 5 Incorrect e. 1, 4, 2, 5, 3 Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 A gene's location along a chromosome is known as which of the following? Choose one answer. a. Locus Correct b. Variant Incorrect c. Trait Incorrect d. Sequence Incorrect e. Allele Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 The symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the Choose one answer. a. large intestine. Incorrect b. pharynx. Incorrect c. small intestine. Incorrect d. liver. Incorrect e. stomach. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 In the thylakoid membranes, what is the main role of the antenna pigment molecules? Choose one answer. a. split water and release oxygen to the reaction-center chlorophyll Incorrect b. harvest photons and transfer light energy to the reaction-center chlorophyll Correct c. synthesize ATP from ADP and Pi Incorrect d. transfer electrons to ferredoxin and then NADPH Incorrect e. concentrate photons within the stroma Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the G for the new reaction? Choose one answer. a. +20 kcal/mol Incorrect b. +40 kcal/mol Incorrect c. -20 kcal/mol Correct d. -40 kcal/mol Incorrect e. 0 kcal/mol Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? Choose one answer. a. cyclic electron flow Correct b. chlorophyll Incorrect c. linear electron flow Incorrect d. photosystem II Incorrect e. photosystem I Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Why does ice float in liquid water? Choose one answer. a. The liquid water molecules have more kinetic energy and thus support the ice. Incorrect b. Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. Correct c. Ice always has air bubbles that keep it afloat. Incorrect d. The ionic bonds between the molecules in ice prevent the ice from sinking. Incorrect e. The crystalline lattice of ice causes it to be denser than liquid water. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. carbonic acid. Incorrect b. carbon dioxide. Incorrect c. plasma buffers. Incorrect d. hemoglobin. Correct e. plasma proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Systems biology is mainly an attempt to Choose one answer. a. speed up the technological application of scientific knowledge. Incorrect b. simplify complex problems by reducing the system into smaller, less complex units. Incorrect 9 Weeks Exam Practice Review of attempt 14 Started on Saturday, 17 January 2009, 11:39 AM Completed on Saturday, 17 January 2009, 11:40 AM Time taken 6 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during Choose one answer. a. neither photosynthesis nor respiration. Correct b. photosynthesis. Incorrect c. photorespiration. Incorrect d. both photosynthesis and respiration. Incorrect e. respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? Choose one answer. a. a mouse species living in a temperate broadleaf forest Incorrect b. a mouse species living in a tropical rain forest Incorrect c. a beaver Incorrect d. a river otter Incorrect e. a mouse species living in the desert Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from Choose one answer. a. ATP synthase to NADP+ reductase. Incorrect b. the stroma to the thylakoid space. Correct c. the intermembrane space to the matrix. Incorrect d. the stroma to the photosystem II. Incorrect e. the matrix to the stroma. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 What are the membrane structures that function in active transport? Choose one answer. a. integral proteins Correct b. cytoskeleton filaments Incorrect c. carbohydrates Incorrect d. cholesterol Incorrect e. peripheral proteins Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following statements concerning unsaturated fats is true? Choose one answer. a. They contain more hydrogen than saturated fats having the same number of carbon atoms. Incorrect b. They generally solidify at room temperature. Incorrect c. They have double bonds in the carbon chains of their fatty acids. Correct d. They have fewer fatty acid molecules per fat molecule. Incorrect e. They are more common in animals than in plants. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate? Choose one answer. a. 10 Incorrect b. 8 Incorrect c. 2 Correct d. 4 Incorrect e. 6 Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following vitamins is correctly associated with its use? Choose one answer. a. vitamin Eprotection of skin from cancer Incorrect b. vitamin Kproduction of white blood cells Incorrect c. vitamin Dcalcium removal from bone Incorrect d. vitamin Aincorporated into the visual pigment of the eye Correct e. vitamin Ccuring rickets Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? Choose one answer. a. limbs, hearts, areas with a good deal of contraction Incorrect b. all ducts, such as those from salivary or sebaceous glands Incorrect c. microvilli, alveoli, and glomeruli Incorrect d. sperm, larynx, and trachea Correct e. egg cells (ova), uterus, and kidneys Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 The average birth weight for human babies is about 3 kg. Which of the following terms best describes this? Choose one answer. a. sexual selection Incorrect b. artificial selection Incorrect c. disruptive selection Incorrect d. stabilizing selection Correct e. directional selection Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? Choose one answer. a. oxidation of pyruvate to acetyl CoA and the citric acid cycle Correct b. oxidative phosphorylation and fermentation Incorrect c. the citric acid cycle and oxidative phosphorylation Incorrect d. glycolysis and the oxidation of pyruvate to acetyl CoA Incorrect e. fermentation and glycolysis Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 During the process of digestion, fats are broken down when fatty acids are detached from glycerol. In addition, proteins are digested to yield amino acids. What do these two processes have in common? Choose one answer. a. They are catalyzed by the same enzyme. Incorrect b. Both occur intracellularly in most organisms. Incorrect c. Each requires ATP as an energy source. Incorrect d. They involve the addition of a water molecule to break bonds (hydrolysis). Correct e. Both require the presence of hydrochloric acid to lower the pH. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white(rr) homozygotes.Which of the following crosses would produce offspring in the ratio of 1 red : 2 roan : 1 white? Choose one answer. a. red × roan Incorrect b. The answer cannot be determined from the information provided. Incorrect c. roan × roan Correct d. red × white Incorrect e. white × roan Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Which of the following is true of metabolism in its entirety? Choose one answer. a. Metabolism utilizes all of an organism's resources Incorrect b. Metabolism depends on a constant supply of energy from food Incorrect c. Metabolism depends on an organism's adequate hydration Incorrect d. Metabolism manages the increase of entropy in an organism Incorrect e. Metabolism is a property of organismal life Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 In vertebrate animals, brown fat tissue's color is due to abundant mitochondria. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few mitochondria. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue? Choose one answer. a. to regulate temperature by converting energy from NADH oxidation to heat Correct b. to allow the animals to regulate their metabolic rate when it is especially hot Incorrect c. to increase the rate of oxidative phosphorylation from its few mitochondria Incorrect d. to allow other membranes of the cell to perform mitochondrial function Incorrect e. to increase the production of ATP synthase Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which term describes centrioles beginning to move apart in animal cells? Choose one answer. a. metaphase Incorrect b. anaphase Incorrect c. prometaphase Incorrect d. prophase Correct e. telophase Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald? Choose one answer. a. 33% Incorrect b. 50% Incorrect c. 25% Incorrect d. 0% Incorrect e. 75% Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 In negative pressure breathing, inhalation results from Choose one answer. a. relaxing the muscles of the rib cage. Incorrect b. contracting the abdominal muscles. Incorrect c. forcing air from the throat down into the lungs. Incorrect d. using muscles of the lungs to expand the alveoli. Incorrect e. contracting the diaphragm. Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? Choose one answer. a. Metaphase I of meiosis Incorrect b. Anaphase of mitosis Incorrect c. Prophase I of meiosis Incorrect d. Anaphase I of meiosis Correct e. Prophase II of meiosis Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. a. nervous system, brain, nervous tissue, nerve cell Correct b. organ system, tissue, molecule, cell Incorrect c. brain, organ system, nerve cell, nervous tissue Incorrect d. organism, organ system, tissue, cell, organ Incorrect e. organ system, nervous tissue, brain Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 The active site of an enzyme is the region that Choose one answer. a. binds allosteric regulators of the enzyme. Incorrect b. is inhibited by the presence of a coenzyme or a cofactor. Incorrect c. binds the products of the catalytic reaction. Incorrect d. is involved in the catalytic reaction of the enzyme. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype? Choose one answer. a. 25% Incorrect b. 75% Incorrect c. 0% Incorrect d. 50% Correct e. 100% Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Which term describes two centrosomes arranged at opposite poles of the cell? Choose one answer. a. telophase Incorrect b. prometaphase Correct c. anaphase Incorrect d. metaphase Incorrect e. prophase Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? Choose one answer. a. 5'-G-C-G-C-3' with 5'-T-A-T-A-3' Incorrect b. 5'-A-G-C-T-3' with 5'-T-C-G-A-3' Incorrect c. All of these pairs are correct. Incorrect d. 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' Incorrect e. 5'-A-T-G-C-3' with 5'-G-C-A-T-3' Correct Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Prokaryotes are classified as belonging to two different domains. What are the domains? Choose one answer. a. Bacteria and Eukarya Incorrect b. Bacteria and Protista Incorrect c. Archaea and Monera Incorrect d. Eukarya and Monera Incorrect e. Bacteria and Archaea Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? Choose one answer. a. compartmentalization of enzymes into defined organelles Correct b. connecting enzymes into large aggregates Incorrect c. exporting enzymes out of the cell Incorrect d. cessation of all enzyme formation Incorrect e. hydrophobic interactions Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following does not occur during the Calvin cycle? Choose one answer. a. regeneration of the CO2 acceptor Incorrect b. carbon fixation Incorrect c. release of oxygen Correct d. oxidation of NADPH Incorrect e. consumption of ATP Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? Choose one answer. a. protonephridia of rotifers Incorrect b. flame-bulb system of flatworms Incorrect c. kidneys of vertebrates Correct d. metanephridia of earthworms Incorrect e. Malpighian tubules of insects Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Each time a molecule of glucose (C6H12O6) is completely oxidized via aerobic respiration, how many oxygen molecules (O2) are required? Choose one answer. a. 1 Incorrect b. 6 Correct c. 38 Incorrect d. 2 Incorrect e. 12 Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of Choose one answer. a. the origin of new species. Incorrect b. the fossil record. Correct c. natural selection. Incorrect d. evolution. Incorrect e. uniformitarianism. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. primary cell wall → plasma membrane → tonoplast → cytoplasm → vacuole Incorrect b. secondary cell wall → plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect c. primary cell wall → plasma membrane → cytoplasm → tonoplast Correct d. tonoplast → primary cell wall → plasma membrane → cytoplasm Incorrect e. plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The residual volume of the lungs decreases. Incorrect b. The epiglottis closes. Incorrect c. The diaphragm contracts. Incorrect d. The volume of the thoracic cavity decreases. Correct e. The rib cage expands. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following is a false statement regarding DNA? Choose one answer. a. Every cell is enclosed by a membrane. Incorrect b. Each chromosome has one very long DNA molecule with hundreds of thousands of genes. Incorrect c. All forms of life are composed of cells that have a membrane-enclosed nucleus. Correct d. Every cell uses DNA as its genetic information. Incorrect e. DNA is the unit of inheritance that is transmitted from parent to offspring. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result? Choose one answer. a. Other male-specific factors influence eye color in flies. Incorrect b. The gene involved is on an autosome. Incorrect c. The gene involved is on the Y chromosome. Incorrect d. The gene involved is on the X chromosome. Correct e. Other female-specific factors influence eye color in flies. Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Independent assortment of chromosomes occurs. Choose one answer. a. The statement is true for mitosis and meiosis II. Incorrect b. The statement is true for mitosis only. Incorrect c. The statement is true for meiosis II only. Incorrect d. The statement is true for meiosis I only. Correct e. The statement is true for mitosis and meiosis I. Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs? Choose one answer. a. Gills allow only unidirectional transport Incorrect b. Water contains much less O2 than air per unit volume. Correct c. Gills allow water to flow in one direction Incorrect d. Water is less dense than air. Incorrect e. Gills have less surface area than lungs. Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Why are carbohydrates and fats considered high energy foods? Choose one answer. a. They can have very long carbon skeletons. Incorrect b. They have a lot of electrons associated with hydrogen. Correct c. They have a lot of oxygen atoms. Incorrect d. They have no nitrogen in their makeup. Incorrect e. They are easily reduced. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Rank the following 1-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide: 1. insertion mutation deep within an intron 2. substitution mutation at the 3rd position of an exonic codon 3. substitution mutation at the 2nd position of an exonic codon 4. deletion mutation within the first exon of the gene Choose one answer. a. 2, 3, 1, 4 Incorrect b. 3, 1, 4, 2 Incorrect c. 1, 2, 3, 4 Incorrect d. 4, 3, 2, 1 Correct e. 2, 1, 4, 3 Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Discovery science uses inductive reasoning to derive generalizations from a large number of specific observations. Answer: True False Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because Choose one answer. a. the hydrolysis of starch to sugar is endergonic. Incorrect b. the activation energy barrier for this reaction cannot be surmounted. Correct c. starch hydrolysis is nonspontaneous. Incorrect d. starch cannot be hydrolyzed in the presence of so much water. Incorrect e. the starch solution has less free energy than the sugar solution. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 The dynamics of any ecosystem include the following major processes: Choose one answer. a. the recycling of chemical nutrients Incorrect b. the flow of energy to producers and the recycling of nutrients Incorrect c. the flow of energy from sunlight to producers and then to consumers Incorrect d. the flow of energy from sunlight to producers and then to consumers, and the recycling of chemical nutrients. Correct e. the flow of energy from sunlight to producers Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 At which level of protein structure are interactions between the side chains (R groups) most important? Choose one answer. a. all of the above Incorrect b. quaternary Incorrect c. tertiary Correct d. primary Incorrect e. secondary Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is true of ammonia? Choose one answer. a. It is the major nitrogenous waste excreted by insects. Incorrect b. It is soluble in water. Correct c. It can be stored as a precipitate. Incorrect d. It is metabolically more expensive to synthesize than urea. Incorrect e. It has low toxicity relative to urea. Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the Choose one answer. a. stomach. Correct b. large intestine. Incorrect c. small intestine. Incorrect d. liver. Incorrect e. pharynx. Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Birds have negative pressure breathing, but it differs from that of mammals and is more efficient because of which of the following reasons? Choose one answer. a. The bird's mouth movements are able to force air into the lungs. Incorrect b. The tidal volume in birds is much larger than in a comparably sized mammal. Incorrect c. The maximum PO2 is significantly higher in bird lungs. Correct d. The brain of the bird maximizes oxygen uptake more efficiently. Incorrect e. The flow of air in a bird's lungs is from posterior to anterior. Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Chromosomes first become visible during which phase of mitosis? Choose one answer. a. prophase Correct b. telophase Incorrect c. anaphase Incorrect d. prometaphase Incorrect e. metaphase Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 Which of the following people synthesized an organic compound, acetic acid, from inorganic substances that had been prepared directly from pure elements? Choose one answer. a. Stanley Miller Incorrect b. Jakob Berzelius Incorrect c. August Kekulé Incorrect d. Friedrich Wohler Incorrect e. Hermann Kolbe Correct Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Which of the following are directly associated with photosystem I? Choose one answer. a. P680 reaction-center chlorophyll Incorrect b. passing electrons to plastoquinone Incorrect c. harvesting of light energy by ATP Incorrect d. extraction of hydrogen electrons from the splitting of water Incorrect e. receiving electrons from plastocyanin Correct Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 If you were to jog a mile a few hours after lunch, which stored fuel would you probably tap? Choose one answer. a. muscle and liver glycogen Correct b. fat stored in adipose tissue Incorrect c. blood proteins Incorrect d. fat stored in the liver Incorrect e. muscle proteins Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. polymers Incorrect b. enzymes Incorrect c. monomers Correct d. peptides Incorrect e. disaccharides Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? Choose one answer. a. artificial selection Incorrect b. stabilizing selection Correct c. directional selection Incorrect d. sexual selection Incorrect e. disruptive selection Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Density-dependent inhibition is explained by which of the following? Choose one answer. a. As cells become more numerous, more and more of them enter the S phase of the cell cycle. Incorrect b. As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. Incorrect c. As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. Correct d. As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. Incorrect e. As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Damage to the sinoatrial node in humans Choose one answer. a. would have a direct effect on blood pressure monitors in the aorta. Incorrect b. would have a negative effect on peripheral resistance. Incorrect c. is a major contributor to heart attacks. Incorrect d. would block conductance between the bundle branches and the Purkinje fibers. Incorrect e. would disrupt the rate and timing of cardiac muscle contractions. Correct Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 How does ADH function at the cellular level? Choose one answer. a. It triggers the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water. Incorrect b. It causes membranes to include more phospholipids that have unsaturated fatty acids. Incorrect c. ADH stimulates the reabsorption of glucose through channel proteins. Incorrect d. It causes an increase in the number of aquaporin molecules of collecting duct cells. Correct e. It decreases the speed at which filtrate flow through the nephron leading to increased reabsorption of water. Incorrect Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the following statements about the 5' end of a polynucleotide strand of DNA is correct? Choose one answer. a. The 5' end has a carboxyl group attached to the number 5 carbon of ribose. Incorrect b. The 5' end has a phosphate group attached to the number 5 carbon of ribose. Correct c. The 5' end has thymine attached to the number 5 carbon of ribose. Incorrect d. The 5' end has a hydroxyl group attached to the number 5 carbon of ribose. Incorrect e. The 5' end is the fifth position on one of the nitrogenous bases. Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 The sodium-potassium pump is called an electrogenic pump because it Choose one answer. a. pumps equal quantities of Na+ and K+ across the membrane. Incorrect b. pumps hydrogen ions out of the cell. Incorrect c. ionizes sodium and potassium atoms. Incorrect d. contributes to the membrane potential. Correct e. is used to drive the transport of other molecules against a concentration gradient. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? Choose one answer. a. an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment Incorrect b. a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium Incorrect c. There is no possibility of having chemical equilibrium in any living cell. Incorrect d. a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive Correct e. a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Which of the following types of molecules are the major structural components of the cell membrane? Choose one answer. a. nucleic acids and proteins Incorrect b. proteins and cellulose Incorrect c. phospholipids and cellulose Incorrect d. phospholipids and proteins Correct e. glycoproteins and cholesterol Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? Choose one answer. a. There will be no significant difference between these groups. Incorrect b. beer the most, salt solution the least Correct c. water the most, beer the least Incorrect d. salt solution the most, water the least Incorrect e. beer the most, water the least Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 9 Weeks Exam Practice Review of attempt 15 Started on Saturday, 17 January 2009, 11:41 AM Completed on Saturday, 17 January 2009, 11:41 AM Time taken 7 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. intestine Incorrect b. liver Incorrect c. gallbladder Incorrect d. stomach Correct e. pancreas Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? Choose one answer. a. sites of energy production in cellular respiration Incorrect b. membrane proteins Incorrect c. ribosomes Incorrect d. cytoskeletons Correct e. cellulose fibers in the cell wall Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following statements describes genomic imprinting? Choose one answer. a. It involves an irreversible alteration in the DNA sequence of imprinted genes. Incorrect b. It is greatest in females because of the larger maternal contribution of cytoplasm. Incorrect c. It may explain the transmission of Duchenne muscular dystrophy. Incorrect d. It explains cases in which the gender of the parent from whom an allele is inherited affects the expression of that allele. Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect b. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect c. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect d. protein function at one site affected by binding at another of its active sites Incorrect e. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following types of reactions would decrease the entropy within a cell? Choose one answer. a. respiration Incorrect b. hydrolysis Incorrect c. dehydration reactions Correct d. digestion Incorrect e. catabolism Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? Choose one answer. a. protists Incorrect b. fungi Incorrect c. plant Incorrect d. animal Incorrect e. archaea Correct Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Cyclic electron flow may be photoprotective (protective to light-induced damage). Which of the following experiments could provide information on this phenomenon? Choose one answer. a. using bacteria with only cyclic flow and measuring the number and types of photosynthetic pigments they have in their membranes Incorrect b. using mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities Correct c. using bacteria that have only cyclic flow and look for their frequency of mutation damage Incorrect d. using plants with only photosystem I operative and measure how much damage occurs at different wavelengths. Incorrect e. using plants that can carry out both linear and cyclic electron flow, or only one or another of thee processes, and measuring their light absorbance Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Approximately what percentage of the energy of glucose (C6H12O6) is transferred to storage in ATP as a result of the complete oxidation of glucose to CO2 and water in cellular respiration? Choose one answer. a. 10% Incorrect b. 25% Incorrect c. 4% Incorrect d. 40% Correct e. 2% Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. Choose one answer. a. NaCl crystals will NOT dissolve in either water or methanol. Incorrect b. NaCl crystals will dissolve readily in water but will not dissolve in methanol. Correct c. When the first crystals of NaCl are added to water or to methanol, they will not dissolve; but as more crystals are added, the crystals will begin to dissolve faster and faster. Incorrect d. Equal amounts of NaCl crystals will dissolve in both water and methanol. Incorrect e. NaCl crystals will dissolve readily in methanol but will not dissolve in water. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 How is photosynthesis similar in C4 and CAM plants? Choose one answer. a. In both cases, only photosystem I is used. Incorrect b. Both types of plants make most of their sugar in the dark. Incorrect c. In both cases, rubisco is not used to fix carbon initially. Correct d. In both cases, thylakoids are not involved in photosynthesis. Incorrect e. Both types of plants make sugar without the Calvin cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Where are the molecules of the electron transport chain found in plant cells? Choose one answer. a. matrix of mitochondria Incorrect b. cytoplasm Incorrect c. thylakoid membranes of chloroplasts Correct d. stroma of chloroplasts Incorrect e. inner membrane of mitochondria Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through several cellular structures. Which of the following correctly describes the order in which these structures will be encountered by the ion? Choose one answer. a. primary cell wall → plasma membrane → cytoplasm → tonoplast Correct b. plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect c. tonoplast → primary cell wall → plasma membrane → cytoplasm Incorrect d. secondary cell wall → plasma membrane → primary cell wall → cytoplasm → tonoplast Incorrect e. primary cell wall → plasma membrane → tonoplast → cytoplasm → vacuole Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 The body is capable of catabolizing many substances as sources of energy. Which of the followingwould be used as an energy source only after the depletion of other sources? Choose one answer. a. calcium phosphate in bone Incorrect b. fat in adipose tissue Incorrect c. glycogen in muscle cells Incorrect d. glucose in the blood Incorrect e. protein in muscle cells Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Where is ATP synthase located in the mitochondrion? Choose one answer. a. inner membrane Correct b. cytosol Incorrect c. outer membrane Incorrect d. mitochondrial matrix Incorrect e. electron transport chain Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 What is the voltage across a membrane called? Choose one answer. a. membrane potential Correct b. electrochemical gradient Incorrect c. chemical gradient Incorrect d. water potential Incorrect e. osmotic potential Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why? Choose one answer. a. CAM plants allow more water loss, while C4 plants allow less CO2 into the plant. Incorrect b. C4 plants allow less water loss but Cam plants but allow more water loss. Incorrect c. Each one minimizes both water loss and rate of photosynthesis. Incorrect d. Each one both minimizes photorespiration and optimizes the Calvin cycle. Correct e. C4 compromises on water loss and CAM compromises on photorespiration. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 How do ADH and RAAS work together in maintaining osmoregulatory homeostasis? Choose one answer. a. Both stimulate the adrenal gland to secrete aldosterone which increases both blood volume and pressure. Incorrect b. Only when they are together in the receptor sites of proximal tubule cells, will reabsorption of essential nutrients back into the blood take place. Incorrect c. ADH monitors osmolarity of the blood and RAAS regulates blood volume. Incorrect d. ADH an RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS removal of water when it is in excess in body fluids. Incorrect e. ADH monitors appropriate osmolarity by reabsorption of water, and RAAS maintains osmolarity by stimulating Na+ reabsorption. Correct Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 The high osmolarity of the renal medulla is maintained by all of the following except Choose one answer. a. diffusion of urea from the collecting duct. Incorrect b. diffusion of salt from the thin segment of the ascending limb of the loop of Henle. Incorrect c. diffusion of salt from the descending limb of the loop of Henle. Correct d. the spatial arrangement of juxtamedullary nephrons. Incorrect e. active transport of salt from the upper region of the ascending limb. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following reactions prevails in red blood cells traveling through alveolar capillaries? (Hb = hemoglobin) Choose one answer. a. Hb + 4 CO2 → Hb(CO2)4 Incorrect b. Hb + 4 O2 → Hb(O2)4 Correct c. H2CO3 → H+ + HCO3- Incorrect d. Hb(O2)4 → Hb + 4 O2 Incorrect e. CO2 + H2O → H2CO3 Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes are permanently altered by the reactions they catalyze. Incorrect b. Enzymes prevent changes in substrate concentrations. Incorrect c. Enzymes increase the rate of a reaction. Correct d. Enzymes change the direction of chemical reactions. Incorrect e. Enzymes decrease the free energy change of a reaction. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Why are cattle able to survive on a diet consisting almost entirely of plant material? Choose one answer. a. They are autotrophic. Incorrect b. Cattle, like the rabbit, reingest their feces. Incorrect c. Cattle saliva has enzymes capable of digesting cellulose. Incorrect d. They manufacture all 15 amino acids out of sugars in the liver. Incorrect e. They have cellulose-digesting, symbiotic microorganisms in chambers of their stomachs. Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of Choose one answer. a. protein-protein interactions. Incorrect b. catalytic feedback. Incorrect c. negative feedback. Correct d. bioinformatic regulation. Incorrect e. positive feedback. Incorrect 9 Weeks Exam Practice Review of attempt 16 Started on Saturday, 17 January 2009, 11:43 AM Completed on Saturday, 17 January 2009, 11:43 AM Time taken 15 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6? Choose one answer. a. 10,000 times more Correct b. 400 times more Incorrect c. 100,000 times more Incorrect d. 4,000 times more Incorrect e. 4 times more Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which is a general term for enzymes that activate or inactivate other proteins by phosphorylating them? Choose one answer. a. PDGF Incorrect b. MPF Incorrect c. Cdk Incorrect d. cyclin Incorrect e. protein kinase Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Quantum dots are small (15—30 nm diameter), bright particles visible using light microscopy. If the dots can be specifically bound to individual proteins on a plasma membrane of a cell, which of the following correctly describes the advantage of using quantum dots in examining proteins? Choose one answer. a. The dots permit visualization of proteins interacting with lipids. Incorrect b. The dots permit the size of the proteins to be determined more precisely. Incorrect c. The dots permit the position of the proteins to be determined more precisely. Incorrect d. The dots permit the motion of the proteins to be determined more precisely. Correct e. The dots permit the average distance between the proteins to be determined more precisely. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Enzymes are Choose one answer. a. nucleic acids. Incorrect b. carbohydrates. Incorrect c. proteins. Correct d. lipids. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following is true regarding saturated fatty acids? Choose one answer. a. They are usually liquid at room temperature. Incorrect b. They have double bonds between carbon atoms of the fatty acids. Incorrect c. They are the principal molecules in lard and butter. Correct d. They are usually produced by plants. Incorrect e. They are the predominant fatty acid in corn oil. Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants Choose one answer. a. the spindles contain microfibrils in addition to microtubules, whereas animal spindles do not contain microfibrils. Incorrect b. spindle poles contain centrioles, whereas spindle poles in animals do not. Incorrect c. chromosomes become attached to the spindle at prophase, whereas in animals chromosomes do not become attached until anaphase. Incorrect d. a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage. Correct e. sister chromatids are identical, but they differ from one another in animals. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? Choose one answer. a. green plants Incorrect b. autotrophs and heterotrophs Incorrect c. photosynthesizers Incorrect d. autotrophs Correct e. producers and primary consumers Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Organic chemistry is a science based on the study of Choose one answer. a. functional groups. Incorrect b. vital forces interacting with matter. Incorrect c. inorganic compounds. Incorrect d. water and its interaction with other kinds of molecules. Incorrect e. carbon compounds. Correct Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with Choose one answer. a. carbon dioxide. Incorrect b. carbonic acid. Incorrect c. plasma proteins. Incorrect d. hemoglobin. Correct e. plasma buffers. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 The application of scientific knowledge for some specific purpose is known as Choose one answer. a. inductive science. Incorrect b. deductive science. Incorrect c. technology. Correct d. pure science. Incorrect e. anthropologic science. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 A woman is found to have 47 chromosomes, including 3 X chromosomes. Which of the following describes her expected phenotype? Choose one answer. a. Sterile female Incorrect b. Excessive emotional instability Incorrect c. Masculine characteristics such as facial hair Incorrect d. Enlarged genital structures Incorrect e. Normal female Correct Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. a. organ system, tissue, molecule, cell Incorrect b. brain, organ system, nerve cell, nervous tissue Incorrect c. nervous system, brain, nervous tissue, nerve cell Correct d. organ system, nervous tissue, brain Incorrect e. organism, organ system, tissue, cell, organ Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 When muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by Choose one answer. a. increase in ethanol. Incorrect b. buildup of pyruvate. Incorrect c. increase in potassium ions. Correct d. increase in sodium ions. Incorrect e. buildup of lactate. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a Choose one answer. a. heterotroph. Incorrect b. chemoautotroph. Incorrect c. CAM plant. Incorrect d. C4 plant. Correct e. C3 plant. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of the following people was the first to synthesize an organic compound, urea, from inorganic starting materials? Choose one answer. a. August Kekulé Incorrect b. Stanley Miller Incorrect c. Hermann Kolbe Incorrect d. Jakob Berzelius Incorrect e. Friedrich Wohler Correct Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Which of the following is true for all exergonic reactions? Choose one answer. a. The reactions are nonspontaneous. Incorrect b. The products have more total energy than the reactants. Incorrect c. The reaction proceeds with a net release of free energy. Correct d. Some reactants will be converted to products. Incorrect e. A net input of energy from the surroundings is required for the reactions to proceed. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Which of the following is true of bile salts? Choose one answer. a. They emulsify fats in the duodenum. Correct b. They are manufactured by the pancreas. Incorrect c. They are enzymes. Incorrect d. They are normally an ingredient of gastric juice. Incorrect e. They increase the efficiency of pepsin action. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A less-than-normal volume of isoosmotic urine would be produced. Incorrect b. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect c. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect d. A greater-than-normal volume of isoosmotic urine would be produced. Correct e. No urine would be produced. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for I. polynucleotide polymerase with low mismatch error rates. II. polynucleotide polymerases without proofreading capability. III. batteries of efficient polynucleotide repair enzymes. IV. polynucleotide polymerases with proofreading capability. V. polynucleotide polymerases with high mismatch error rates. Choose one answer. a. II and V Correct b. II, III and V Incorrect c. I and IV Incorrect d. I only Incorrect e. I, III, and IV Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes decrease the free energy change of a reaction. Incorrect b. Enzymes prevent changes in substrate concentrations. Incorrect c. Enzymes change the direction of chemical reactions. Incorrect d. Enzymes are permanently altered by the reactions they catalyze. Incorrect e. Enzymes increase the rate of a reaction. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. a. they are subunits of important polymers. Incorrect b. only those animals use the nutrients. Incorrect c. they cannot be manufactured by the organism. Correct d. they are necessary coenzymes. Incorrect e. only some foods contain them. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 A molecule that is phosphorylated Choose one answer. a. has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate. Incorrect b. has a decreased chemical reactivity; it is less likely to provide energy for cellular work. Incorrect c. has an increased chemical reactivity; it is primed to do cellular work. Correct d. has less energy than before its phosphorylation and therefore less energy for cellular work. Incorrect e. has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 The first genes on Earth were probably Choose one answer. a. DNA produced by reverse transcriptase from abiotically produced RNA. Incorrect b. oligopeptides located within protobionts. Incorrect c. RNA produced by autocatalytic, proteinaceous enzymes. Incorrect d. auto-catalytic RNA molecules. Correct e. DNA molecules whose information was transcribed to RNA and later translated in polypeptides. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Which of the following membrane activities require energy from ATP hydrolysis? Choose one answer. a. facilitated diffusion. Incorrect b. Na+ ions moving out of the cell Correct c. movement of glucose molecules Incorrect d. movement of water into a paramecium Incorrect e. movement of water into a cell Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following sequences correctly represents the flow of electrons during photosynthesis? Choose one answer. a. NADPH → electron transport chain → O2 Incorrect b. NADPH → chlorophyll → Calvin cycle Incorrect c. NADPH → O2 → CO2 Incorrect d. H2O → NADPH → Calvin cycle Correct e. H2O → photosystem I → photosystem II Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Pulse is a direct measure of Choose one answer. a. stroke volume. Incorrect b. cardiac output. Incorrect c. heart rate. Correct d. blood pressure. Incorrect e. breathing rate. Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 In an animal species known for endurance running rather than fast sprinting, which of the following would you expect? Choose one answer. a. a relatively slow heart rate in order to lower oxygen consumption Incorrect b. a much higher rate of oxygen consumption for its size Correct c. an increase of storage of oxygen in myoglobin of its muscles Incorrect d. a slower rate of oxygen consumption so that its breathing will not have to be accelerated Incorrect e. a lower pressure of oxygen in the alveoli Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Reduction of NADP+ occurs during Choose one answer. a. photosynthesis. Correct b. respiration. Incorrect c. neither photosynthesis nor respiration. Incorrect d. photorespiration. Incorrect e. both photosynthesis and respiration. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 After a membrane freezes and then thaws, it often becomes leaky to solutes. The most reasonable explanation for this is that Choose one answer. a. the integrity of the lipid bilayer is broken when the membrane freezes. Correct b. the lipid bilayer loses its fluidity when it freezes. Incorrect c. aquaporins can no longer function after freezing. Incorrect d. transport proteins become nonfunctional during freezing. Incorrect e. the solubility of most solutes in the cytoplasm decreases on freezing. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? Choose one answer. a. derive sufficient energy from fermentation Incorrect b. transform lactate to pyruvate again Incorrect c. remove lactate from the blood Incorrect d. remove oxygen from lactate Incorrect e. continue aerobic metabolism when skeletal muscle cannot Correct Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility, and death, usually of coronary artery disease, at an average age of approximately 13. Patients, who look very old even as children, do not live to reproduce. Which of the following represents the most likely assumption? Choose one answer. a. The disorder may be due to mutation in a single protein-coding gene. Correct b. Successive generations of a family will continue to have more and more cases over time. Incorrect c. All cases must occur in relatives; therefore, there must be only one mutant allele. Incorrect d. The disease is autosomal dominant. Incorrect e. Each patient will have had at least one affected family member in a previous generation. Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 The symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the Choose one answer. a. pharynx. Incorrect b. stomach. Correct c. large intestine. Incorrect d. small intestine. Incorrect e. liver. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. Choose one answer. a. 4 → 2 → 1 → 3 Incorrect b. 4 → 2 → 3 → 1 Incorrect c. 2 → 4 → 3 → 1 Incorrect d. 2 → 4 → 1 → 3 Correct e. 4 → 1 → 2 → 3 Incorrect Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Cellular respiration harvests the most chemical energy from which of the following? Choose one answer. a. substrate-level phosphorylation Incorrect b. chemiosmotic phosphorylation Correct c. generating carbon dioxide and oxygen in the electron transport chain Incorrect d. transferring electrons from organic molecules to pyruvate Incorrect e. converting oxygen to ATP Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 How does a noncompetitive inhibitor decrease the rate of an enzyme reaction? Choose one answer. a. by decreasing the activation energy of the reaction Incorrect b. by changing the free energy change of the reaction Incorrect c. by changing the shape of a reactant Correct d. by binding at the active site of the enzyme Incorrect e. by acting as a coenzyme for the reaction Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the women teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. What might be among their conclusions? Choose one answer. a. The elderly donor samples represent cells no longer capable of any cell division. Incorrect b. The patient samples should have had the lowest response but did not, so the experiment is invalid. Incorrect c. The young women showed these results because they have poorer nutrition. Incorrect d. The young men had higher response because they are generally healthier. Incorrect e. The elderly persons' samples demonstrated their lowered immune responses. Correct Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Birds secrete uric acid as their nitrogenous waste because uric acid Choose one answer. a. requires little water for nitrogenous waste disposal which is conducive to the function of flight in terms of weight. Correct b. excretion allows birds to live in desert environments. Incorrect c. is metabolically less expensive to synthesize than other excretory products. Incorrect d. is readily soluble in water. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? Choose one answer. a. XCXC and XCY Incorrect b. XCXC and XcY Incorrect c. XcXc and XcY Incorrect d. XcXcand XCY Incorrect e. XCXcand XCY Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Physical anthropologists locating the jaw bones of previously unknown vertebrate animal fossils are often able to assess the animal's diet especially because of clues from which of the following? Choose one answer. a. the position of muscle attachment sites Incorrect b. the size of the mouth opening Incorrect c. the prevalence of specific kinds of teeth Correct d. the evidence of food molecules still present Incorrect e. whether the mouth is the most anterior structure Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which of the following organelles functions in this compartmentalization? Choose one answer. a. lysosome Correct b. peroxisome Incorrect c. chloroplast Incorrect d. central vacuole Incorrect e. glyoxysome Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which structure passes urine to the renal pelvis? Choose one answer. a. collecting duct Correct b. proximal tubule Incorrect c. Bowman's capsule Incorrect d. loop of Henle Incorrect e. glomerulus Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following are directly associated with photosystem I? Choose one answer. a. harvesting of light energy by ATP Incorrect b. extraction of hydrogen electrons from the splitting of water Incorrect c. passing electrons to plastoquinone Incorrect d. P680 reaction-center chlorophyll Incorrect e. receiving electrons from plastocyanin Correct Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 A type of protein critical to all cells is organic catalysts called Choose one answer. a. nutrients. Incorrect b. feedback inhibitors. Incorrect c. feedback activators. Incorrect d. metabolites. Incorrect e. enzymes. Correct Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 All of the following arepartof aprokaryotic cell except Choose one answer. a. a cell wall. Incorrect b. ribosomes. Incorrect c. a plasma membrane. Incorrect d. DNA. Incorrect e. an endoplasmic reticulum. Correct Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method. Answer: True False Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 During which phases of mitosis are chromosomes composed of two chromatids? Choose one answer. a. from interphase through anaphase Incorrect b. from anaphase through telophase Incorrect c. from metaphase through telophase Incorrect d. from G1 of interphase through metaphase Incorrect e. from G2 of interphase through metaphase Correct Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then Choose one answer. a. fluids will tend to accumulate in tissues. Correct b. the pH of the interstitial fluids will increase. Incorrect c. plasma proteins will escape through the endothelium of the capillaries. Incorrect d. most carbon dioxide will be bound to hemoglobin and carried away from tissues. Incorrect e. hemoglobin will not release oxygen. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Which one of the following is extremely important for water conservation in mammals? Choose one answer. a. urethra Incorrect b. Bowman's capsule Incorrect c. podocytes Incorrect d. ureter Incorrect e. juxtamedullary nephrons Correct Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? Choose one answer. a. The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. Correct b. The sizes of the structures in adult members of both species are similar in size. Incorrect c. Both species are well adapted to their particular environments. Incorrect d. Both species reproduce sexually. Incorrect e. The two species live at great distance from each other. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the G for the new reaction? Choose one answer. a. -40 kcal/mol Incorrect b. +20 kcal/mol Incorrect c. 0 kcal/mol Incorrect d. -20 kcal/mol Correct e. +40 kcal/mol Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? Choose one answer. a. 8 Incorrect b. 4 Incorrect c. 32 Correct d. 64 Incorrect e. 16 Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Science requires that hypothesis be testable and falsifiable and that observations be repeatable. Answer: True False Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 If a human interphase nucleus contains three Barr bodies, it can be assumed that the person Choose one answer. a. has hemophilia. Incorrect b. has Down syndrome. Incorrect c. has Turner syndrome. Incorrect d. is a male. Incorrect e. has four X chromosomes. Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Mendel's second law of independent assortment has its basis in which of the following events of meiosis I? Choose one answer. a. Alignment of tetrads at the equator Correct b. Crossing over Incorrect c. Synapsis of homologous chromosomes Incorrect d. Separation of cells at telophase Incorrect e. Separation of homologs at anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Which of the following is/are a cause(s) of vasoconstriction? Choose one answer. a. lying down after standing Incorrect b. standing after lying down Incorrect c. stress or hormone concentration Correct d. increased blood pressure Incorrect e. histamine secretion Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. ADP. Incorrect b. NAD+. Incorrect c. pyruvate. Incorrect d. oxygen. Correct e. water. Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. birds. Incorrect b. desert tortoises. Incorrect c. frogs. Incorrect d. kangaroo rats. Correct e. humans. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 What is the change in free energy of a system at chemical equilibrium? Choose one answer. a. no net change Correct b. greatly decreasing Incorrect c. slightly increasing Incorrect d. slightly decreasing Incorrect e. greatly increasing Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of Choose one answer. a. paedomorphosis. Incorrect b. an evolutionary trend. Incorrect c. adaptive radiation. Incorrect d. exaptation. Correct e. changes in the Hox gene expression. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Most nutrients absorbed into the lymph or bloodstream are in which form? Choose one answer. a. monomers Correct b. enzymes Incorrect c. disaccharides Incorrect d. polymers Incorrect e. peptides Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of attempt 17 Started on Saturday, 17 January 2009, 11:44 AM Completed on Saturday, 17 January 2009, 11:44 AM Time taken 9 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 Which of the following animals is incorrectly paired with its feeding mechanism? Choose one answer. a. snakebulk feeder Incorrect b. baleen whalesuspension feeder Incorrect c. lionsubstrate feeder Correct d. aphidfluid feeder Incorrect e. clamsuspension feeder Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount ATP in a cell would be expected to Choose one answer. a. inhibit the enzyme and thus increase the rates of glycolysis and the citric acid cycle. Incorrect b. activate the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Incorrect c. inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle. Correct d. inhibit the enzyme and thus increase the rate of glycolysis and the concentration of citrate. Incorrect e. activate the enzyme and increase the rates of glycolysis and the citric acid cycle. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is Choose one answer. a. the flow of electrons down the electron transport chain. Incorrect b. the affinity of oxygen for electrons. Incorrect c. the oxidation of glucose and other organic compounds. Incorrect d. the H+ concentration gradient across the inner mitochondrial membrane. Correct e. the transfer of phosphate to ADP. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 Which of the following is an example of qualitative data? Choose one answer. a. The contents of the stomach are mixed every 20 seconds. Incorrect b. The fish swam in a zig-zag motion. Correct c. The temperature decreased from 20°C to 15°C. Incorrect d. The plant's height is 25 centimeters (cm). Incorrect e. The six pairs of robins hatched an average of three chicks. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? Choose one answer. a. pyruvate Incorrect b. succinyl CoA Incorrect c. malate or fumarate Incorrect d. α-ketoglutarate Incorrect e. acetyl CoA Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following is true for all exergonic reactions? Choose one answer. a. The reaction proceeds with a net release of free energy. Correct b. Some reactants will be converted to products. Incorrect c. The reactions are nonspontaneous. Incorrect d. A net input of energy from the surroundings is required for the reactions to proceed. Incorrect e. The products have more total energy than the reactants. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following are directly associated with photosystem I? Choose one answer. a. passing electrons to plastoquinone Incorrect b. harvesting of light energy by ATP Incorrect c. extraction of hydrogen electrons from the splitting of water Incorrect d. P680 reaction-center chlorophyll Incorrect e. receiving electrons from plastocyanin Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which structure descends deep into the renal medulla only in juxtamedullary nephrons? Choose one answer. a. proximal convoluted tubule Incorrect b. Bowman's capsule Incorrect c. glomerulus Incorrect d. loop of Henle Correct e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 How does the hemocyanin of arthropods and molluscs differ from the hemoglobin of mammals? Choose one answer. a. Hemocyanin includes cyanic acid. Incorrect b. The oxygen dissociation curve for hemocyanin is linear. Incorrect c. Hemocyanin carries appreciably more carbon dioxide. Incorrect d. Hemocyanin has protein coupled to copper rather than iron. Correct e. The protein of hemocyanin is not bound to metal. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Speciation Choose one answer. a. can involve changes involving a single gene. Correct b. must begin with the geographic isolation of a small, frontier population. Incorrect c. proceeds at a uniform tempo across all taxa. Incorrect d. occurs only by the accumulation of genetic change over vast expanses of time. Incorrect e. occurs at such a slow pace that no one has ever observed the emergence of new species. Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following is true of ammonia? Choose one answer. a. It has low toxicity relative to urea. Incorrect b. It is the major nitrogenous waste excreted by insects. Incorrect c. It is soluble in water. Correct d. It can be stored as a precipitate. Incorrect e. It is metabolically more expensive to synthesize than urea. Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following is a fat-soluble vitamin? Choose one answer. a. iodine Incorrect b. vitamin B12 Incorrect c. vitamin A Correct d. calcium Incorrect e. vitamin C Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 A major evolutionary episode that corresponds in time most closely with the formation of Pangaea was the Choose one answer. a. Pleistocene ice ages. Incorrect b. Permian extinctions. Correct c. Cretaceous extinctions. Incorrect d. origin of humans. Incorrect e. Cambrian explosion. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 In which animal does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body? Choose one answer. a. mollusc Incorrect b. frog Correct c. insect Incorrect d. annelid Incorrect e. fish Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Which of these naturalists synthesized a concept of natural selection independently of Darwin? Choose one answer. a. Alfred Wallace Correct b. Charles Lyell Incorrect c. Gregor Mendel Incorrect d. John Henslow Incorrect e. Thomas Malthus Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Males are more often affected by sex-linked traits than females because Choose one answer. a. female hormones such as estrogen often compensate for the effects of mutations on the X. Incorrect b. males are hemizygous for the X chromosome. Correct c. mutations on the Y chromosome often worsen the effects of X-linked mutations. Incorrect d. X chromosomes in males generally have more mutations than X chromosomes in females. Incorrect e. male hormones such as testosterone often alter the effects of mutations on the X chromosome. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? Choose one answer. a. XcXcand XCY Incorrect b. XCXcand XCY Correct c. XCXC and XcY Incorrect d. XcXc and XcY Incorrect e. XCXC and XCY Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 We can be sure that a mole of table sugar and a mole of vitamin C are equal in their Choose one answer. a. number of atoms. Incorrect b. number of molecules. Correct c. mass in grams. Incorrect d. volume. Incorrect e. mass in daltons. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which of the following factors would tend to increase membrane fluidity? Choose one answer. a. a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses Incorrect b. a greater proportion of unsaturated phospholipids Correct c. a lower temperature Incorrect d. a relatively high protein content in the membrane Incorrect e. a greater proportion of saturated phospholipids Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following? Choose one answer. a. 63 chromosomes, each with three chromatids Incorrect b. 63 chromosomes in 31 1/2 pairs Incorrect c. 21 chromosome pairs and 21 unique chromosomes Incorrect d. 63 chromosomes in 21 sets of 3 Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Starting with one molecule of glucose, the "net" products of glycolysis are Choose one answer. a. 6 CO2, 6 H2O, 36 ATP, and 2 citrate. Incorrect b. 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O. Incorrect c. 6 CO2, 6 H2O, 2 ATP, and 2 pyruvate. Incorrect d. 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. Incorrect e. 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. Correct Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? Choose one answer. a. The sugar molecule is different. Incorrect b. The nitrogen-containing base is different. Incorrect c. There is no difference. Correct d. The number of phosphates is three instead of one. Incorrect e. The number of phosphates is three instead of two. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle? Choose one answer. a. a gain of NADPH Incorrect b. regeneration of ATP from ADP Incorrect c. inactivation of RuBP carboxylase enzyme Incorrect d. regeneration of rubisco Correct e. addition of a pair of electrons from NADPH Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Countercurrent exchange in the fish gill helps to maximize which of the following? Choose one answer. a. endocytosis Incorrect b. active transport Incorrect c. osmosis Incorrect d. blood pressure Incorrect e. diffusion Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 What is the typical osmolarity of human blood? Choose one answer. a. 500 mosm/L Incorrect b. 30 mosm/L Incorrect c. 300 mosm/L Correct d. 200 mosm/L Incorrect e. 100 mosm/L Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Where does the Calvin cycle take place? Choose one answer. a. thylakoid membrane Incorrect b. outer membrane of the chloroplast Incorrect c. stroma of the chloroplast Correct d. chlorophyll molecule Incorrect e. cytoplasm surrounding the chloroplast Incorrect Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 If the pH of a solution is increased from pH 5 to pH 7, it means that the Choose one answer. a. concentration of OH- is one-hundredth (0.01X) what it was at pH 5. Incorrect b. concentration of OH- is 100 times greater than what it was at pH 5. Correct c. concentration of H+ is twice (2X) what it was at pH 5. Incorrect d. concentration of H+ is 100 times greater and the concentration of OH- is one-hundredth what they were at pH 5. Incorrect e. concentration of H+ is half (1/2) what it was at pH 5. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Which of the following is a statement of the first law of thermodynamics? Choose one answer. a. Energy cannot be created or destroyed. Correct b. Kinetic energy is stored energy that results from the specific arrangement of matter. Incorrect c. The entropy of the universe is constant. Incorrect d. Energy cannot be transferred or transformed. Incorrect e. The entropy of the universe is decreasing. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 People with sickle-cell trait Choose one answer. a. All of the above Correct b. produce normal and abnormal hemoglobin. Incorrect c. have increased resistance to malaria. Incorrect d. are heterozygous for the sickle-cell allele. Incorrect e. are usually healthy. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Systems biology is mainly an attempt to Choose one answer. a. build high-throughput machines for the rapid acquisition of biological data. Incorrect b. speed up the technological application of scientific knowledge. Incorrect c. simplify complex problems by reducing the system into smaller, less complex units. Incorrect d. construct models of the behavior of entire biological systems. Correct e. understand the integration of all levels of biological organization from molecules to the biosphere. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 After surgical removal of an infected gallbladder, a person must be especially careful to restrict dietary intake of Choose one answer. a. starch. Incorrect b. protein. Incorrect c. water. Incorrect d. sugar. Incorrect e. fat. Correct Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Foods eaten by animals are most often composed largely of macromolecules. This requires the animals to have methods for which of the following? Choose one answer. a. demineralization Incorrect b. elimination Incorrect c. enzymatic hydrolysis Correct d. regurgitation Incorrect e. dehydration synthesis Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 Which of the events listed below occur in the light reactions of photosynthesis? Choose one answer. a. NADP is produced. Incorrect b. ATP is phosphorylated to yield ADP. Incorrect c. carbon dioxide is incorporated into PGA. Incorrect d. NADPH is reduced to NADP+. Incorrect e. light is absorbed and funneled to reaction-center chlorophyll a. Correct Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 How many electron pairs does carbon share in order to complete its valence shell? Choose one answer. a. 4 Correct b. 1 Incorrect c. 3 Incorrect d. 2 Incorrect e. 8 Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which branch of biology is concerned with the naming and classifying of organisms? Choose one answer. a. schematic biology Incorrect b. genomics Incorrect c. taxonomy Correct d. evolution Incorrect e. informatics Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Diffusion rate is proportional to the square of the distance molecules/ions travel. Which of the following would therefore be preferable for a midsize multicellular organism? Choose one answer. a. a system for facilitated diffusion to maximize materials that could be exchanged Incorrect b. direct exchange of nutrients with the surrounding medium Incorrect c. a system for bringing nutrients into contact with cells, and another system for bringing O2 to cells Incorrect d. a system to circulate gases, nutrients, and wastes to and from cells Correct e. a system of individualized exchange tubules for each cell group Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? Choose one answer. a. glycolysis Correct b. oxidative phosphorylation Incorrect c. chemiosmosis Incorrect d. electron transport Incorrect e. the citric acid cycle Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 One liter of a solution pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4? Choose one answer. a. 10,000 times more Incorrect b. 100 times more Incorrect c. 5 times more Incorrect d. 1,000 times more Incorrect e. 100,000 times more Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal cells. The most reasonable explanation for this observation is that Choose one answer. a. plant cells are capable of having a much higher surface-to-volume ratio than animal cells. Incorrect b. the basic functions of plant cells are very different from those of animal cells. Incorrect c. plant cells have a much more highly convoluted (folded) plasma membrane than animal cells. Incorrect d. plant cells contain a large vacuole that reduces the volume of the cytoplasm. Correct e. animal cells are more spherical, while plant cells are elongated. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 In mechanism, photophosphorylation is most similar to Choose one answer. a. substrate-level phosphorylation in glycolysis. Incorrect b. carbon fixation. Incorrect c. oxidative phosphorylation in cellular respiration. Correct d. the Calvin cycle. Incorrect e. reduction of NADP+. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Life is diverse. How many species are estimated to be presently on the earth? Choose one answer. a. 18,000,000 Incorrect b. 180,000,000 Incorrect c. 1,800 Incorrect d. 180,000 Incorrect e. 1,800,000 Correct Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 The cyclin component of MPF is destroyed toward the end of this phase: Choose one answer. a. G1 Incorrect b. G0 Incorrect c. M Correct d. S Incorrect e. G2 Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 The human genome is minimally contained in which of the following? Choose one answer. a. The entire DNA of a single human Incorrect b. Every human cell Correct c. The entire human population Incorrect d. Each human gene Incorrect e. Each human chromosome Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following are adaptations to a carnivorous diet? Choose one answer. a. bile salts Correct b. ingestion of feces Incorrect c. amylase Incorrect d. broad, flat molars Incorrect e. a rumen Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 What are the membrane structures that function in active transport? Choose one answer. a. cholesterol Incorrect b. carbohydrates Incorrect c. integral proteins Correct d. peripheral proteins Incorrect e. cytoskeleton filaments Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 A controlled experiment is one in which Choose one answer. a. there are at least two groups, one differing from the other by two or more variables. Incorrect b. the experiment is repeated many times to ensure that the results are accurate. Incorrect c. there is one group for which the scientist controls all variables. Incorrect d. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data. Incorrect e. there are at least two groups, one of which does not receive the experimental treatment. Correct Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? Choose one answer. a. A less-than-normal volume of isoosmotic urine would be produced. Incorrect b. No urine would be produced. Incorrect c. A greater-than-normal volume of hyperosmotic urine would be produced. Incorrect d. A greater-than-normal volume of isoosmotic urine would be produced. Correct e. A less-than-normal volume of hypoosmotic urine would be produced. Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 If the curve shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations, then which of these is (are) probably occurring? 1. immigration or emigration 2. directional selection 3. adaptation 4. genetic drift 5. disruptive selection Choose one answer. a. 2 and 3 Correct b. 4 only Incorrect c. 1, 2, and 3 Incorrect d. 1 only Incorrect e. 4 and 5 Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 Which of the following statements is false for the class of biological molecules known as lipids? Choose one answer. a. They contain more energy than proteins and carbohydrates. Incorrect b. They contain waxes and steroids. Incorrect c. They are not true polymers. Incorrect d. They are soluble in water. Correct e. They are an important constituent of cell membranes. Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. frogs. Incorrect b. desert tortoises. Incorrect c. humans. Incorrect d. kangaroo rats. Correct e. birds. Incorrect Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 Breathing is usually regulated by Choose one answer. a. hemoglobin levels in the blood. Incorrect b. CO2 and O2 concentration and pH-level sensors. Correct c. the lungs and the larynx. Incorrect d. erythropoietin levels in the blood. Incorrect e. the concentration of red blood cells. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you expect to be the most likely consequence? Choose one answer. 9 Weeks Exam Practice Review of attempt 18 Started on Saturday, 17 January 2009, 11:45 AM Completed on Saturday, 17 January 2009, 11:45 AM Time taken 7 secs Raw score 0/60 (0%) Grade 0 out of a maximum of 100 Question 1 Marks: 1 How many molecules of glucose (C6H2O6 molecular mass =180 daltons) would be present in one mole of glucose? Choose one answer. a. 23 × 1014 Incorrect b. 6.02 × 1023 Correct c. 342 Incorrect d. 180 × 1014 Incorrect e. 24 Incorrect Incorrect Marks for this submission: 0/1. Question 2 Marks: 1 Which of the following statements is a correct distinction between autotrophs and heterotrophs? Choose one answer. a. Only heterotrophs require oxygen. Incorrect b. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Correct c. Only heterotrophs require chemical compounds from the environment. Incorrect d. Cellular respiration is unique to heterotrophs. Incorrect e. Only heterotrophs have mitochondria. Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Which of the following lung volumes would be different in a person at rest compared with when the person exercises? Choose one answer. a. residual volume Incorrect b. total lung capacity Incorrect c. tidal volume Correct d. vital capacity Incorrect e. All of the above would be different. Incorrect Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The main source of energy for producers in an ecosystem is Choose one answer. a. light energy. Correct b. ATP. Incorrect c. thermal energy. Incorrect d. chemical energy. Incorrect e. kinetic energy. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 What is the typical osmolarity of human blood? Choose one answer. a. 100 mosm/L Incorrect b. 200 mosm/L Incorrect c. 30 mosm/L Incorrect d. 500 mosm/L Incorrect e. 300 mosm/L Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which of the following best demonstrates the unity among all organisms? Choose one answer. a. emergent properties Incorrect b. the structure and function of DNA Correct c. matching DNA nucleotide sequences Incorrect d. natural selection Incorrect e. descent with modification Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Birds secrete uric acid as their nitrogenous waste because uric acid Choose one answer. a. is metabolically less expensive to synthesize than other excretory products. Incorrect b. excretion allows birds to live in desert environments. Incorrect c. is readily soluble in water. Incorrect d. requires little water for nitrogenous waste disposal which is conducive to the function of flight in terms of weight. Correct Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 A biologist discovers two populations of wolf spiders whose members appear identical. Members of one population are found in the leaf litter deep within the woods. Members of the other population are found in the grass at the edge of the woods. The biologist decides to designate the members of the two populations as two separate species. Which species concept is this biologist most closely utilizing? Choose one answer. a. biological Incorrect b. phylogenetic Incorrect c. ecological Correct d. morphological Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? Choose one answer. a. Anaphase I of meiosis Correct b. Anaphase of mitosis Incorrect c. Metaphase I of meiosis Incorrect d. Prophase I of meiosis Incorrect e. Prophase II of meiosis Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows: Choose one answer. a. -G, -H, -S Incorrect b. +G, +H, +S Incorrect c. -G, +H, +S Incorrect d. +G, -H, -S Incorrect e. +G, +H, -S Correct Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? Choose one answer. a. active transport pumps Incorrect b. facilitated diffusion Correct c. exocytosis Incorrect d. simple diffusion Incorrect e. phagocytosis Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which of the following is used to diagnose hypertension in adults? Choose one answer. a. measurement of the LDL/HDL ratio in peripheral blood Incorrect b. percent of blood volume made up of platelets Incorrect c. measurement of fatty deposits on the endothelium of arteries Incorrect d. number of leukocytes per mm3 of blood Incorrect e. blood pressure of >140 mm Hg systolic and/or >90 diastolic Correct Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 The mammalian trachea and esophagus both connect to the Choose one answer. a. rectum. Incorrect b. large intestine. Incorrect c. pharynx. Correct d. epiglottis. Incorrect e. stomach. Incorrect Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and Choose one answer. a. an increasing number of viable, fertile hybrids is produced over the course of generations Correct b. a decreasing number of viable, fertile hybrids is produced over the course of generations. Incorrect c. a constant number of viable, fertile hybrids is produced over the course of generations. Incorrect d. the hybrid zone is inhospitable to hybrid survival. Incorrect e. their chromosomes are no longer homologous enough to permit meiosis. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Each of the following has a better chance of influencing gene frequencies in small populations than in large populations, but which one most consistently requires a small population as a precondition for its occurrence? Choose one answer. a. Non-random mating Incorrect b. Mutation Incorrect c. Natural selection Incorrect d. Genetic drift Correct e. Gene flow Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes Choose one answer. a. oxidized. Correct b. an oxidizing agent. Incorrect c. dehydrogenated. Incorrect d. hydrogenated. Incorrect e. reduced. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 What part(s) of the digestive system have secretions with a pH of 2? Choose one answer. a. liver Incorrect b. pancreas Incorrect c. stomach Correct d. small intestine Incorrect e. mouth Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that Choose one answer. a. it is possible to obtain large numbers of progeny from any given cross. Incorrect b. peas show easily observed variations in a number of characters, such as pea shape and flower color. Incorrect c. it is possible to control matings between different pea plants. Incorrect d. peas have an unusually long generation time. Correct e. many of the observable characters that vary in pea plants are controlled by single genes. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Glycolysis is thought to be one of the most ancient of metabolic processes. Which statement supports this idea? Choose one answer. a. Glycolysis is the most widespread metabolic pathway. Correct b. Glycolysis neither uses nor needs O2. Incorrect c. The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed organelle. Incorrect d. Ancient prokaryotic cells, the most primitive of cells, made extensive use of glycolysis long before oxygen was present in Earth's atmosphere. Incorrect e. Glycolysis is found in all eukaryotic cells. Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 After telophase I of meiosis, the chromosomal makeup of each daughter cell is Choose one answer. a. diploid, and the chromosomes are each composed of a single chromatid. Incorrect b. tetraploid, and the chromosomes are each composed of two chromatids. Incorrect c. haploid, and the chromosomes are each composed of a single chromatid. Incorrect d. diploid, and the chromosomes are each composed of two chromatids. Incorrect e. haploid, and the chromosomes are each composed of two chromatids. Correct Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Which of the following reactions prevails in red blood cells traveling through alveolar capillaries? (Hb = hemoglobin) Choose one answer. a. CO2 + H2O → H2CO3 Incorrect b. H2CO3 → H+ + HCO3- Incorrect c. Hb + 4 O2 → Hb(O2)4 Correct d. Hb + 4 CO2 → Hb(CO2)4 Incorrect e. Hb(O2)4 → Hb + 4 O2 Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the G for the new reaction? Choose one answer. a. +40 kcal/mol Incorrect b. +20 kcal/mol Incorrect c. -40 kcal/mol Incorrect d. -20 kcal/mol Correct e. 0 kcal/mol Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 A number of systems for pumping across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't often hydrolyze ATP unless they are simultaneously transporting ions. Small increases in calcium ions in the cytosol trigger a number of different intracellular reactions, so the cells must keep the calcium concentration quite low. Muscle cells also transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a muscle cell cytosol has a free calcium ion concentration of 10-7 in a resting cell, while the concentration in the SR can be 10-2, then how is the ATPase acting? Choose one answer. a. ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. Correct b. The ATP must be powering an inflow of calcium from the outside of the cell into the SR. Incorrect c. The route of calcium ions must be from SR to the cytosol, to the cell's environment. Incorrect d. ATP must be transferring Pi to the SR to enable this to occur. Incorrect e. The calcium ions must be diffusing back into the SR along the concentration gradient. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? Choose one answer. a. 100 mL of freshly-squeezed orange juice Incorrect b. 100 mL of freshly-brewed coffee Incorrect c. 100 mL of pure water Incorrect d. 100 mL of household cleanser containing 0.5M ammonia Correct e. 100 mL of tomato juice Incorrect Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following statements best distinguishes hypotheses from theories in science? Choose one answer. a. Theories are hypotheses that have been proved. Incorrect b. Hypotheses are guesses; theories are correct answers. Incorrect c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. Correct d. Hypotheses and theories are essentially the same thing. Incorrect e. Theories are proved true in all cases; hypotheses are usually falsified by tests. Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be Choose one answer. a. to determine if they have thylakoids in the chloroplasts. Incorrect b. to test for production of either sucrose or starch. Incorrect c. to test for CO2 fixation in the dark. Incorrect d. to do experiments to generate an action spectrum. Incorrect e. to test for liberation of O2 in the light. Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 What is a karyotype? Choose one answer. a. The collection of all the mutations present within the genome of an individual Incorrect b. A display of every pair of homologous chromosomes within a cell, organized according to size and shape Correct c. The set of unique physical characteristics that define an individual Incorrect d. A system of classifying cell nuclei Incorrect e. The combination of chromosomes found in a gamete Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 At what temperature is water at its densest? Choose one answer. a. 212°C Incorrect b. 0°C Incorrect c. 100°C Incorrect d. 32°C Incorrect e. 4°C Correct Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 In negative pressure breathing, inhalation results from Choose one answer. a. relaxing the muscles of the rib cage. Incorrect b. using muscles of the lungs to expand the alveoli. Incorrect c. contracting the abdominal muscles. Incorrect d. forcing air from the throat down into the lungs. Incorrect e. contracting the diaphragm. Correct Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 If neutral variation is truly "neutral," then it should have no effect on Choose one answer. a. relative fitness. Correct b. gene diversity. Incorrect c. average heterozygosity. Incorrect d. nucleotide diversity. Incorrect e. our ability to measure the rate of evolution. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following does not occur during mitosis? Choose one answer. a. separation of sister chromatids Incorrect b. replication of the DNA Correct c. separation of the spindle poles Incorrect d. condensation of the chromosomes Incorrect e. spindle formation Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2→ 6 CO2 + 6 H2O + Energy Choose one answer. a. CO2 is reduced and O2 is oxidized. Incorrect b. O2 is oxidized and H2O is reduced. Incorrect c. C6H12O6 is oxidized and O2 is reduced. Correct d. O2 is reduced and CO2 is oxidized. Incorrect e. C6H12O6 is reduced and CO2 is oxidized. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 The decline of MPF activity at the end of mitosis is due to Choose one answer. a. decreased synthesis of cyclin. Incorrect b. an increase in the cell's volume-to-genome ratio. Incorrect c. synthesis of DNA. Incorrect d. the destruction of the protein kinase Cdk. Incorrect e. the degradation of cyclin. Correct Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 When a disease is said to have a multifactorial basis, it means that Choose one answer. a. it is caused by a gene with a large number of alleles. Incorrect b. it has many different symptoms. Incorrect c. it tends to skip a generation. Incorrect d. it affects a large number of people. Incorrect e. both genetic and environmental factors contribute to the disease. Correct Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 Which of the following is an example of polygenic inheritance? Choose one answer. a. White and purple flower color in peas Incorrect b. Pink flowers in snapdragons Incorrect c. Skin pigmentation in humans Correct d. The ABO blood groups in humans Incorrect e. Huntington's disease in humans Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20 kg of water how many degrees Celsius? Choose one answer. a. 10.0°C Correct b. 1.0°C Incorrect c. 2.0°C Incorrect d. 0.2°C Incorrect e. 20.0°C Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would be the effect? Choose one answer. a. The heart rate would be decreased. Incorrect b. Only the ventricles would contract. Incorrect c. Atria and ventricles would contract at about the same time. Correct d. Only the atria would contract. Incorrect e. No apparent effect on heart activity would be observed. Incorrect Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 The peroxisome gets its name from its interaction with hydrogen peroxide. If a liver cell is detoxifying alcohol and some other poisons, it does so by removal of hydrogen from the molecules. What, then, do the enzymes of the peroxisome do? Choose one answer. a. transfer the harmful substances to the mitochondria Incorrect b. transfer the hydrogens to oxygen molecules Correct c. combine the hydrogen with ATP Incorrect d. use the hydrogen to break down hydrogen peroxide Incorrect Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 An electron loses potential energy when it Choose one answer. a. attaches itself to NAD+. Incorrect b. increases its activity as an oxidizing agent. Incorrect c. shifts to a more electronegative atom. Correct d. increases its kinetic energy. Incorrect e. shifts to a less electronegative atom. Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Physical anthropologists locating the jaw bones of previously unknown vertebrate animal fossils are often able to assess the animal's diet especially because of clues from which of the following? Choose one answer. a. the prevalence of specific kinds of teeth Correct b. the position of muscle attachment sites Incorrect c. the evidence of food molecules still present Incorrect d. whether the mouth is the most anterior structure Incorrect e. the size of the mouth opening Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following is true of the evolution of cell membranes? Choose one answer. a. An individual organism selects its preferred type of cell membrane for particular functions. Incorrect b. Cell membranes have stopped evolving now that they are fluid mosaics. Incorrect c. As populations of organisms evolve, different properties of their cell membranes are selected for or against. Correct d. The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids. Incorrect e. Cell membranes cannot evolve if proteins do not. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following is an example of cooperativity? Choose one answer. a. protein function at one site affected by binding at another of its active sites Incorrect b. the effect of increasing temperature on the rate of an enzymatic reaction Incorrect c. binding of an ATP molecule along with one of the substrate molecules in an active site Incorrect d. a molecule binding at one unit of a tetramer allowing faster binding at each of the other three Correct e. the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? Choose one answer. a. photosystem I Incorrect b. photosystem II Incorrect c. cyclic electron flow Correct d. chlorophyll Incorrect e. linear electron flow Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which of the following is the correct sequence of these events in the origin of life? I. formation of protobionts II. synthesis of organic monomers III. synthesis of organic polymers IV. formation of DNA-based genetic systems Choose one answer. a. III, II, I, IV Incorrect b. II, III, I, IV Correct c. I, III, II, IV Incorrect d. IV, III, I, II Incorrect e. I, II, III, IV Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 What is a chromatid? Choose one answer. a. a replicate chromosome Correct b. a special region that holds two centromeres together Incorrect c. a chromosome found outside the nucleus Incorrect d. another name for the chromosomes found in genetics Incorrect e. a chromosome in G1 of the cell cycle Incorrect Incorrect Marks for this submission: 0/1. Question 46 Marks: 1 African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? Choose one answer. a. The highly toxic urea makes the pool uninhabitable to potential competitors. Incorrect b. Small stagnant pools do not provide enough water to dilute the toxic ammonia. Correct c. Urea takes less energy to synthesize than ammonia. Incorrect d. Urea makes lungfish tissue hypoosmotic to the pool. Incorrect e. Urea forms an insoluble precipitate. Incorrect Incorrect Marks for this submission: 0/1. Question 47 Marks: 1 Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following? Choose one answer. a. His reading of the scientific literature current in the field Incorrect b. His experiments with the breeding of plants such as peas Correct c. His discussions of heredity with his colleagues at major universities Incorrect d. His reading and discussion of Darwin's Origin of Species Incorrect e. The understanding of particulate inheritance he learned from renowned scientists of his time Incorrect Incorrect Marks for this submission: 0/1. Question 48 Marks: 1 Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of Choose one answer. a. positive feedback. Correct b. enzymatic catalysis. Incorrect c. negative feedback. Incorrect d. feedback inhibition. Incorrect e. a bioinformatic system. Incorrect Incorrect Marks for this submission: 0/1. Question 49 Marks: 1 For this pair of items, choose the option that best describes their relationship. (A) The probability of finding chitin in fungal cell walls (B) The probability of finding chitin in arthropod exoskeletons Choose one answer. a. Item (A) may stand in more than one of the above relations to item (B). Incorrect b. Item (A) is exactly or very approximately equal to item (B). Correct c. Item (A) is greater than item (B). Incorrect d. Item (A) is less than item (B). Incorrect Incorrect Marks for this submission: 0/1. Question 50 Marks: 1 Generation of proton gradients across membranes occurs during Choose one answer. a. photosynthesis. Incorrect b. neither photosynthesis nor respiration. Incorrect c. respiration. Incorrect d. photorespiration. Incorrect e. both photosynthesis and respiration. Correct Incorrect Marks for this submission: 0/1. Question 51 Marks: 1 When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? Choose one answer. a. It is lost to the environment. Correct b. It is transported to specific organs such as the brain. Incorrect c. It is used to store energy as more ATP. Incorrect d. It is used to power yet more cellular work. Incorrect e. It is used to generate ADP from nucleotide precursors. Incorrect Incorrect Marks for this submission: 0/1. Question 52 Marks: 1 Which of the following is true of ammonia? Choose one answer. a. It has low toxicity relative to urea. Incorrect b. It is the major nitrogenous waste excreted by insects. Incorrect c. It is soluble in water. Correct d. It can be stored as a precipitate. Incorrect e. It is metabolically more expensive to synthesize than urea. Incorrect Incorrect Marks for this submission: 0/1. Question 53 Marks: 1 In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? Choose one answer. a. energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix Incorrect b. No external source of energy is required because the reaction is exergonic. Incorrect c. energy released as electrons flow through the electron transport system Incorrect d. energy released from substrate-level phosphorylation Incorrect e. energy released from movement of protons through ATP synthase Correct Incorrect Marks for this submission: 0/1. Question 54 Marks: 1 Which of the following is not an observation or inference on which Darwin's theory of natural selection is based? Choose one answer. a. Individuals whose inherited characteristics best fit them to the environment will generally produce more offspring. Incorrect b. There is heritable variation among individuals. Incorrect c. A population can become adapted to its environment. Incorrect d. Because of overproduction of offspring, there is competition for limited resources. Incorrect e. Poorly adapted individuals never produce offspring. Correct Incorrect Marks for this submission: 0/1. Question 55 Marks: 1 Cell membranes are asymmetrical. Which of the following is a most likely explanation? Choose one answer. a. Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. Correct b. The "innerness" and "outerness" of membrane surfaces are predetermined by genes. Incorrect c. The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium. Incorrect d. Cell membranes communicate signals from one organism to another. Incorrect e. Proteins can only span cell membranes if they are hydrophobic. Incorrect Incorrect Marks for this submission: 0/1. Question 56 Marks: 1 A cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. Assuming that glucose is not actively transported into the cell, which of the following terms describes the tonicity of the external solution relative to the cytoplasm of the cell? Choose one answer. a. isotonic Correct b. hypertonic Incorrect c. hypotonic Incorrect d. turgid Incorrect e. flaccid Incorrect Incorrect Marks for this submission: 0/1. Question 57 Marks: 1 Compared to the seawater around them, most marine invertebrates are Choose one answer. a. hypoosmotic and isoosmotic. Incorrect b. isoosmotic. Correct c. hyperosmotic and isoosmotic. Incorrect d. hypoosmotic. Incorrect e. hyperosmotic. Incorrect Incorrect Marks for this submission: 0/1. Question 58 Marks: 1 In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur? Choose one answer. a. The molecular environment lets it boost an electron to a higher energy level and also to transfer the electron to another molecule. Correct b. These chlorophyll a molecules are associated with higher concentrations of ATP. Incorrect c. The potential energy of the electron has to go back to the ground state. Incorrect d. The action spectrum of that molecule is such that it is different from other molecules of chlorophyll. Incorrect e. Each pigment molecule has to be able to act independently to excite electrons. Incorrect Incorrect Marks for this submission: 0/1. Question 59 Marks: 1 An animal that migrates great distances would obtain the greatest benefit from storing its energy as Choose one answer. a. carbohydrates. Incorrect b. minerals. Incorrect c. fats. Correct d. amino acids. Incorrect e. proteins. Incorrect Incorrect Marks for this submission: 0/1. Question 60 Marks: 1 Adult lampreys attach onto large fish and feed regularly on their body fluids. Given this continuous supply of food, which one of the following is most likely missing in lampreys? Choose one answer. a. pancreas Incorrect b. liver Incorrect c. gallbladder Incorrect d. stomach Correct e. intestine Incorrect Incorrect Marks for this submission: 0/1. 9 Weeks Exam Practice Review of attempt 1 Started on Thursday, 15 January 2009, 09:00 AM Completed on Thursday, 15 January 2009, 09:03 AM Time taken 3 mins 11 secs Raw score 2/60 (3%) Grade 3.33 out of a maximum of 100 Question 1 Marks: 1 Which of the following lung volumes would be different in a person at rest compared with when the person exercises? Choose one answer. a. All of the above would be different. Incorrect b. residual volume Incorrect c. vital capacity Incorrect d. total lung capacity Incorrect e. tidal volume Correct Correct Marks for this submission: 1/1. Question 2 Marks: 1 How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis? Choose one answer. a. They have half the amount of cytoplasm and twice the amount of DNA. Incorrect b. They have twice the amount of cytoplasm and half the amount of DNA. Incorrect c. They have the same number of chromosomes and half the amount of DNA. Incorrect d. They have half the number of chromosomes and half the amount of DNA. Incorrect e. They have half the number of chromosomes and one-fourth the amount of DNA. Correct Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 Prokaryotes are classified as belonging to two different domains. What are the domains? Choose one answer. a. Bacteria and Eukarya Incorrect b. Eukarya and Monera Incorrect c. Archaea and Monera Incorrect d. Bacteria and Archaea Correct e. Bacteria and Protista Incorrect Correct Marks for this submission: 1/1. Question 4 Marks: 1 The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is Choose one answer. a. oxygen. Correct b. water. Incorrect c. ADP. Incorrect d. pyruvate. Incorrect e. NAD+. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 Which of the following animals generally has the lowest volume of urine production? Choose one answer. a. a shark inhabiting freshwater Lake Nicaragua Incorrect b. a marine bony fish Correct c. a salmon in freshwater Incorrect d. a marine shark Incorrect e. a freshwater bony fish Incorrect Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 Which is a true statement concerning genetic variation? Choose one answer. a. A population that has a higher average heterozygosity has less genetic variation than one with a larger average heterozygosity. Incorrect b. It must be present in a population before natural selection can act upon the population. Correct c. It arises in response to changes in the environment. Incorrect d. It is created by the direct action of natural selection. Incorrect e. It tends to be reduced by the processes involved when diploid organisms produce gametes. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 Which of the following occurs with the exhalation of air from human lungs? Choose one answer. a. The volume of the thoracic cavity decreases. Correct b. The rib cage expands. Incorrect c. The epiglottis closes. Incorrect d. The diaphragm contracts. Incorrect e. The residual volume of the lungs decreases. Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of the following statements correctly defines a kilocalorie? Choose one answer. a. the amount of heat required to raise the temperature of 1,000 g of water by 1°F Incorrect b. the amount of heat required to raise the temperature of 1 g of water by 1°C Incorrect c. the amount of heat required to raise the temperature of 1 kg of water by 1°C Correct d. the amount of heat required to raise the temperature of 1 kg of water by 1°F Incorrect e. the amount of heat required to raise the temperature of 1 g of water by 1°F Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 In glycolysis, for each molecule of glucose oxidized to pyruvate Choose one answer. a. 6 molecules of ATP are used and 6 molecules of ATP are produced. Incorrect b. 4 molecules of ATP are used and 2 molecules of ATP are produced. Incorrect c. 2 molecules of ATP are used and 4 molecules of ATP are produced. Correct d. 2 molecules of ATP are used and 2 molecules of ATP are produced. Incorrect e. 2 molecules of ATP are used and 6 molecules of ATP are produced. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 What causes the decrease in the amount of cyclin at a specific point in the cell cycle? Choose one answer. a. the changing ratio of cytoplasm to genome Incorrect b. an increase in production once the restriction point is passed Incorrect c. the cascade of increased production once its protein is phosphorylated by Cdk Incorrect d. its destruction by a process initiated by the activity of its complex with a cyclin Correct e. the binding of PDGF to receptors on the cell surface Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 The pH of the stomach is low enough and the protease activity high enough that the cells of the stomach itself are at risk of self-digestion. This is prevented by which of the following? Choose one answer. a. mucus secretion and active mitosis of epithelial cells Correct b. a sufficient colony of H. pylori Incorrect c. high level of secretion from parietal cells Incorrect d. secretions entering the stomach from the pancreas Incorrect e. high level of secretion by chief cells Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model? Choose one answer. a. Unsaturated lipids are excluded from the membranes. Incorrect b. The membrane is only fluid across a very narrow temperature range. Incorrect c. Proteins rarely move, even though they possibly can do so. Incorrect d. The concentration of protein molecules is now known to be much higher. Correct e. The proteins are known to be made of only acidic amino acids. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method. Answer: True False Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests Choose one answer. a. that each offspring has the same alleles. Incorrect b. that the parents were both heterozygous. Correct c. incomplete dominance. Incorrect d. that a blending of traits has occurred. Incorrect e. that the parents were true-breeding for contrasting traits. Incorrect Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? Choose one answer. a. Cancer cells are no longer density dependent. Incorrect b. Cancer cells are no longer anchorage dependent. Incorrect c. Chromosomally abnormal cells can still go through cell cycle checkpoints. Correct d. Transformation introduces new chromosomes into cells. Incorrect e. Chromosomally abnormal cells still have normal metabolism. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 Some nutrients are considered "essential" in the diets of certain animals because Choose one answer. a. they are subunits of important polymers. Incorrect b. only those animals use the nutrients. Incorrect c. they are necessary coenzymes. Incorrect d. only some foods contain them. Incorrect e. they cannot be manufactured by the organism. Correct Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 In animals, meiosis results in gametes, and fertilization results in Choose one answer. a. gametophytes. Incorrect b. zygotes. Correct c. sporophytes. Incorrect d. spores. Incorrect e. clones. Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which of the following statements regarding enzymes is true? Choose one answer. a. Enzymes decrease the free energy change of a reaction. Incorrect b. Enzymes prevent changes in substrate concentrations. Incorrect c. Enzymes increase the rate of a reaction. Correct d. Enzymes are permanently altered by the reactions they catalyze. Incorrect e. Enzymes change the direction of chemical reactions. Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Which structure is common to plant and animal cells? Choose one answer. a. central vacuole Incorrect b. chloroplast Incorrect c. wall made of cellulose Incorrect d. centriole Incorrect e. mitochondrion Correct Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of Choose one answer. a. ATP, NADH, and pyruvate. Incorrect b. ATP, CO2, and ethanol (ethyl alcohol). Correct c. ATP, pyruvate, and acetyl CoA. Incorrect d. ATP, pyruvate, and oxygen. Incorrect e. ATP, CO2, and lactate. Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to sea water. They are therefore considered by many to be osmoconformers because of the unusual way they maintain homeostasis. They osmoregulate by Choose one answer. a. using their gills and kidneys to rid themselves of sea salts. Incorrect b. synthesizing trimethylamine oxide, a chemical that speeds salt removal from cells. Incorrect c. possessing a special adaptation that allows their cells to operate at an unusually high salt concentration. Incorrect d. tolerating high urea concentrations that balance internal salt concentrations to sea water osmolarity. Correct e. monitoring dehydration at the cellular level with special gated aquaporins. Incorrect Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 Blood returning to the mammalian heart in a pulmonary vein drains first into the Choose one answer. a. right atrium. Incorrect b. left ventricle Incorrect c. left atrium. Correct d. right ventricle Incorrect e. vena cava. Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Why are hydrocarbons insoluble in water? Choose one answer. a. They exhibit considerable molecular complexity and diversity. Incorrect b. They are hydrophilic. Incorrect c. They are lighter than water. Incorrect d. The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. Correct e. The majority of their bonds are polar covalent carbon-to-hydrogen linkages. Incorrect Incorrect Marks for this submission: 0/1. Question 24 Marks: 1 Foods eaten by animals are most often composed largely of macromolecules. This requires the animals to have methods for which of the following? Choose one answer. a. dehydration synthesis Incorrect b. elimination Incorrect c. regurgitation Incorrect d. demineralization Incorrect e. enzymatic hydrolysis Correct Incorrect Marks for this submission: 0/1. Question 25 Marks: 1 Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? Choose one answer. a. ATP and NADPH Correct b. electrons and H+ Incorrect c. ADP, Pi, and NADP+ Incorrect d. H2O and O2 Incorrect e. CO2 and glucose Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following is a correct sequence of levels in life's hierarchy, proceeding downward from an individual animal? Choose one answer. a. brain, organ system, nerve cell, nervous tissue Incorrect b. organism, organ system, tissue, cell, organ Incorrect c. organ system, nervous tissue, brain Incorrect d. organ system, tissue, molecule, cell Incorrect e. nervous system, brain, nervous tissue, nerve cell Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 The mathematical expression for the change in free energy of a system is G =H-TS. Which of the following is (are) correct? Choose one answer. a. S is the change in enthalpy, a measure of randomness. Incorrect b. H is the change in entropy, the energy available to do work. Incorrect c. G is the change in free energy. Correct d. T is the temperature in degrees Celsius. Incorrect Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 A man with Klinefelter syndrome (47, XXY) is expected to have any of the following EXCEPT Choose one answer. a. possible breast enlargement. Incorrect b. lower sperm count. Incorrect c. female body characteristics. Incorrect d. increased testosterone. Correct e. long limbs. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 Which of the following is true of enzymes? Choose one answer. a. Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. Incorrect b. Enzyme function is increased if the three-dimensional structure or conformation of an enzyme is altered. Incorrect c. Enzymes increase the rate of chemical reaction by lowering activation energy barriers. Correct d. Enzymes may require a nonprotein cofactor or ion for catalysis to take speed up more appreciably than if the enzymes act alone. Incorrect Incorrect Marks for this submission: 0/1. Question 30 Marks: 1 Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? Choose one answer. a. All organisms show heritable variation. Incorrect b. All organisms use essentially the same genetic code. Correct c. All organisms reproduce. Incorrect d. All organisms require energy. Incorrect e. All organisms have undergone evolution. Incorrect Incorrect Marks for this submission: 0/1. Question 31 Marks: 1 Which of the following are capable of converting light energy to chemical energy? Choose one answer. a. leucoplasts Incorrect b. peroxisomes Incorrect c. chloroplasts Correct d. Golgi bodies Incorrect e. mitochondria Incorrect Incorrect Marks for this submission: 0/1. Question 32 Marks: 1 There are 40 individuals in population 1, all of which have genotype A1A1, and there are 25 individuals in population 2, all of genotype A2A2. Assume that these populations are located far from one another and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is mostly likely an example of Choose one answer. a. gene flow. Incorrect b. genetic drift. Correct c. discrete variation. Incorrect d. disruptive selection. Incorrect e. directional selection. Incorrect Incorrect Marks for this submission: 0/1. Question 33 Marks: 1 The experimental approach taken in current biological investigations presumes that Choose one answer. a. a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods. Incorrect b. although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods. Incorrect c. living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. Incorrect d. simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms. Incorrect e. living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena. Correct Incorrect Marks for this submission: 0/1. Question 34 Marks: 1 Cellular respiration harvests the most chemical energy from which of the following? Choose one answer. a. substrate-level phosphorylation Incorrect b. chemiosmotic phosphorylation Correct c. generating carbon dioxide and oxygen in the electron transport chain Incorrect d. transferring electrons from organic molecules to pyruvate Incorrect e. converting oxygen to ATP Incorrect Incorrect Marks for this submission: 0/1. Question 35 Marks: 1 What are the products of linear photophosphorylation? Choose one answer. a. ATP and NADPH Correct b. ATP and P700 Incorrect c. heat and fluorescence Incorrect d. P700 and P680 Incorrect e. ADP and NADP Incorrect Incorrect Marks for this submission: 0/1. Question 36 Marks: 1 Hydrophobic substances such as vegetable oil are Choose one answer. a. polar substances that repel water molecules. Incorrect b. nonpolar substances that repel water molecules. Correct c. nonpolar substances that have an attraction for water molecules. Incorrect d. charged molecules that hydrogen-bond with water molecules. Incorrect e. polar substances that have an affinity for water. Incorrect Incorrect Marks for this submission: 0/1. Question 37 Marks: 1 Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet? Choose one answer. a. They interbreed freely and produce fertile hybrid offspring. Incorrect b. They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap. Incorrect c. They interbreed in the region of overlap, but produce sterile offspring. Incorrect d. They no longer attempt to interbreed. Incorrect e. They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations. Correct Incorrect Marks for this submission: 0/1. Question 38 Marks: 1 Which of the following is likely to lead to an increase in the concentration of ATP in a cell? Choose one answer. a. the cell's increased transport of materials to the environment Incorrect b. an increased amino acid concentration Incorrect c. an increase in a cell's anabolic activity Incorrect d. an increased influx of cofactor molecules Incorrect e. an increase in a cell's catabolic activity Correct Incorrect Marks for this submission: 0/1. Question 39 Marks: 1 Prokaryotic and eukaryotic cells generally have which of the following features in common? Choose one answer. a. ribosomes Correct b. flagella or cilia that contain microtubules Incorrect c. linear chromosomes made of DNA and protein Incorrect d. a membrane-bounded nucleus Incorrect e. a cell wall made of cellulose Incorrect Incorrect Marks for this submission: 0/1. Question 40 Marks: 1 Enzymes are Choose one answer. a. proteins. Correct b. lipids. Incorrect c. carbohydrates. Incorrect d. nucleic acids. Incorrect Incorrect Marks for this submission: 0/1. Question 41 Marks: 1 Which of the following statements best describes the relationship between photosynthesis and respiration? Choose one answer. a. Respiration is the reversal of the biochemical pathways of photosynthesis. Incorrect b. ATP molecules are produced in photosynthesis and used up in respiration. Incorrect c. Respiration is anabolic and photosynthesis is catabolic. Incorrect d. Photosynthesis stores energy in complex organic molecules, while respiration releases it. Correct e. Photosynthesis occurs only in plants and respiration occurs only in animals. Incorrect Incorrect Marks for this submission: 0/1. Question 42 Marks: 1 Which of the following enzymes works most effectively at a very low pH? Choose one answer. a. pancreatic amylase Incorrect b. trypsin Incorrect c. pepsin Correct d. salivary amylase Incorrect e. pancreatic lipase Incorrect Incorrect Marks for this submission: 0/1. Question 43 Marks: 1 Which structure increases the reabsorption of Na+ when stimulated by aldosterone? Choose one answer. a. distal tubules Correct b. Bowman's capsule Incorrect c. loop of Henle Incorrect d. proximal tubule Incorrect e. collecting duct Incorrect Incorrect Marks for this submission: 0/1. Question 44 Marks: 1 Which metabolic pathway is common to both cellular respiration and fermentation? Choose one answer. a. oxidative phosphorylation Incorrect b. glycolysis Correct c. the citric acid cycle Incorrect d. chemiosmosis Incorrect e. the oxidation of pyruvate to acetyl CoA Incorrect Incorrect Marks for this submission: 0/1. Question 45 Marks: 1 9 Weeks Exam Practice Review of attempt 2 Started on Saturday, 17 January 2009, 11:30 AM Completed on Saturday, 17 January 2009, 11:31 AM Time taken 33 secs Raw score 3/60 (5%) Grade 5 out of a maximum of 100 Question 1 Marks: 1 What is the main nitrogenous waste excreted by birds? Choose one answer. a. ammonia Incorrect b. uric acid Correct c. urea Incorrect d. nitrate Incorrect e. nitrite Incorrect Correct Marks for this submission: 1/1. Question 2 Marks: 1 Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level? Choose one answer. a. ecosystem, cell, population, tissue, organism, organ system Incorrect b. cell, community, population, organ system, molecule, organelle Incorrect c. molecule, cell, organ system, population, ecosystem, biosphere Correct d. organelle, tissue, biosphere, ecosystem, population, organism Incorrect e. organism, community, biosphere, molecule, tissue, organ Incorrect Incorrect Marks for this submission: 0/1. Question 3 Marks: 1 When muscle cells are oxygen deprived, the heart still pumps. What must the heart cells be able to do? Choose one answer. a. remove lactate from the blood Incorrect b. remove oxygen from lactate Incorrect c. derive sufficient energy from fermentation Incorrect d. transform lactate to pyruvate again Incorrect e. continue aerobic metabolism when skeletal muscle cannot Correct Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the women teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. What might be among their conclusions? Choose one answer. a. The young men had higher response because they are generally healthier. Incorrect b. The young women showed these results because they have poorer nutrition. Incorrect c. The patient samples should have had the lowest response but did not, so the experiment is invalid. Incorrect d. The elderly persons' samples demonstrated their lowered immune responses. Correct e. The elderly donor samples represent cells no longer capable of any cell division. Incorrect Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 The most concentrated urine is excreted by Choose one answer. a. desert tortoises. Incorrect b. birds. Incorrect c. frogs. Incorrect d. humans. Incorrect e. kangaroo rats. Correct Incorrect Marks for this submission: 0/1. Question 6 Marks: 1 What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries? Choose one answer. a. The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood. Correct b. The osmotic pressure of the blood is greater than the hydrostatic pressure of the interstitial fluid. Incorrect c. The osmotic pressure of the interstitial fluid is greater than that of the blood. Incorrect d. The osmotic pressure of the interstitial fluid is greater than the hydrostatic pressure of the blood. Incorrect e. The hydrostatic pressure of the blood is less than that of the interstitial fluid. Incorrect Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white(rr) homozygotes.Which of the following crosses would produce offspring in the ratio of 1 red : 2 roan : 1 white? Choose one answer. a. roan × roan Correct b. red × white Incorrect c. white × roan Incorrect d. The answer cannot be determined from the information provided. Incorrect e. red × roan Incorrect Incorrect Marks for this submission: 0/1. Question 8 Marks: 1 Which of the following is a function of plasma proteins in humans? Choose one answer. a. aerobic metabolism Incorrect b. maintenance of blood osmotic pressure Correct c. oxygen transport Incorrect d. transport of water-soluble lipids Incorrect e. gas exchange Incorrect Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Calico cats are female because Choose one answer. a. only females can have Barr bodies. Incorrect b. multiple crossovers on the Y chromosome prevent orange pigment production. Incorrect c. a male inherits only one of the two X-linked genes controlling hair color. Correct d. the Y chromosome has a gene blocking orange coloration. Incorrect e. the males die during embryonic development. Incorrect Incorrect Marks for this submission: 0/1. Question 10 Marks: 1 Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes? Choose one answer. a. the flow of electrons from photosystem II to photosystem I Incorrect b. the absorption of light energy by chlorophyll Incorrect c. the reduction of NADP+ Incorrect d. the synthesis of ATP Correct e. the splitting of water Incorrect Incorrect Marks for this submission: 0/1. Question 11 Marks: 1 Which of the following animals is incorrectly paired with its feeding mechanism? Choose one answer. a. snakebulk feeder Incorrect b. baleen whalesuspension feeder Incorrect c. aphidfluid feeder Incorrect d. lionsubstrate feeder Correct e. clamsuspension feeder Incorrect Incorrect Marks for this submission: 0/1. Question 12 Marks: 1 Which statement about natural selection is most correct? Choose one answer. a. Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well. Incorrect b. Natural selection is the sole means by which populations can evolve. Incorrect c. Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals. Correct d. Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes. Incorrect e. Adaptations beneficial at one time should generally be beneficial during all other times as well. Incorrect Incorrect Marks for this submission: 0/1. Question 13 Marks: 1 This is the shortest part of the cell cycle: Choose one answer. a. S Incorrect b. G2 Incorrect c. G1 Incorrect d. G0 Incorrect e. M Correct Incorrect Marks for this submission: 0/1. Question 14 Marks: 1 Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply? Choose one answer. a. Photosystem II may have evolved to be more photoprotective. Incorrect b. Cyclic flow must be the most necessary of the two processes. Incorrect c. Cyclic flow must be more primitive than linear flow of electrons. Incorrect d. Photosystem II must have been selected against in some species. Incorrect e. Photosystem I must be more ancestral. Correct Incorrect Marks for this submission: 0/1. Question 15 Marks: 1 An inversion in a human chromosome often results in no demonstrable phenotypic effect in the individual. What else may occur? Choose one answer. a. The individual is more likely to get cancer. Incorrect b. All inverted chromosomes are deleted. Incorrect c. Some abnormal gametes may be formed. Correct d. There is an increased frequency of mutation. Incorrect e. There may be deletions later in life. Incorrect Incorrect Marks for this submission: 0/1. Question 16 Marks: 1 The symbiotic microbes that help nourish a ruminant live mainly in specialized regions of the Choose one answer. a. large intestine. Incorrect b. pharynx. Incorrect c. liver. Incorrect d. stomach. Correct e. small intestine. Incorrect Incorrect Marks for this submission: 0/1. Question 17 Marks: 1 If the digestive systems of animals are to provide the energy needed for ATP and biosynthesis, which of the following diets would be most suitable? Choose one answer. a. a diet low in lipids and high in protein Incorrect b. a diet that maximizes vitamins and minerals Incorrect c. a low-calorie diet with large intake of fluids, especially water Incorrect d. a diet that matches the "food pyramid" for the species Correct e. a high protein, low carbohydrate diet Incorrect Incorrect Marks for this submission: 0/1. Question 18 Marks: 1 Which action could produce a carbonyl group? Choose one answer. a. the replacement of the OH of a carboxyl group with hydrogen Correct b. the addition of a sulfhydryl to a carboxyl Incorrect c. the addition of a hydroxyl to a phosphate Incorrect d. the replacement of the nitrogen of an amine with oxygen Incorrect e. the addition of a thiol to a hydroxyl Incorrect Incorrect Marks for this submission: 0/1. Question 19 Marks: 1 Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? Choose one answer. a. metaphase Correct b. prometaphase Incorrect c. prophase Incorrect d. telophase Incorrect e. anaphase Incorrect Incorrect Marks for this submission: 0/1. Question 20 Marks: 1 Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy (ΔG = -686 kcal/mol). The phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate efficiency of cellular respiration for a "mutant" organism that produces only 29 moles of ATP for every mole of glucose oxidized, rather than the usual 36-38 moles of ATP? Choose one answer. a. 0.4% Incorrect b. 25% Incorrect c. 40% Incorrect d. 30% Correct e. 60% Incorrect Incorrect Marks for this submission: 0/1. Question 21 Marks: 1 Charles Darwin presented verifiable evidence that supported the view that life can arise by spontaneous generation. Answer: True False Incorrect Marks for this submission: 0/1. Question 22 Marks: 1 A blood vessel has the following characteristics: outer layer of connective tissue, a thick layer of smooth muscle with elastic fibers, no valves. It is which of the following? Choose one answer. a. a portal vessel Incorrect b. a vein Incorrect c. an artery Correct d. a venule Incorrect e. a capillary Incorrect Incorrect Marks for this submission: 0/1. Question 23 Marks: 1 Which of the following terms best describes when the phenotype of the heterozygote differs from the phenotypes of both homozygotes? Choose one answer. a. Multiple alleles Incorrect b. Incomplete dominance Correct c. Pleiotropy Incorrect d. Epistasis Incorrect Correct Marks for this submission: 1/1. Question 24 Marks: 1 Where do the enzymatic reactions of the Calvin cycle take place? Choose one answer. a. outer membrane of the chloroplast Incorrect b. electron transport chain Incorrect c. stroma of the chloroplast Correct d. thylakoid membranes Incorrect e. thylakoid space Incorrect Correct Marks for this submission: 1/1. Question 25 Marks: 1 In which blood vessel is glucose concentration likely to vary the most? Choose one answer. a. abdominal artery Incorrect b. pulmonary veins Incorrect c. hepatic portal vessel Correct d. coronary arteries Incorrect e. hepatic vein, which drains the liver Incorrect Incorrect Marks for this submission: 0/1. Question 26 Marks: 1 Which of the following is likely to lead to an increase in the concentration of ATP in a cell? Choose one answer. a. an increase in a cell's anabolic activity Incorrect b. the cell's increased transport of materials to the environment Incorrect c. an increased influx of cofactor molecules Incorrect d. an increased amino acid concentration Incorrect e. an increase in a cell's catabolic activity Correct Incorrect Marks for this submission: 0/1. Question 27 Marks: 1 Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? Choose one answer. a. NH3 Incorrect b. H2CO3 Incorrect c. NaCl Incorrect d. HCl Incorrect e. NaOH Correct Incorrect Marks for this submission: 0/1. Question 28 Marks: 1 Birds have negative pressure breathing, but it differs from that of mammals and is more efficient because of which of the following reasons? Choose one answer. a. The maximum PO2 is significantly higher in bird lungs. Correct b. The bird's mouth movements are able to force air into the lungs. Incorrect c. The tidal volume in birds is much larger than in a comparably sized mammal. Incorrect d. The flow of air in a bird's lungs is from posterior to anterior. Incorrect e. The brain of the bird maximizes oxygen uptake more efficiently. Incorrect Incorrect Marks for this submission: 0/1. Question 29 Marks: 1 The first genes on Earth were probably Choose one answer. a. RNA produced by autocatalytic, proteinaceous enzymes. Incorrect b. DNA produced by reverse transcriptase from abiotically produced RNA. Incorrect c. oligopeptides located within protobionts. Incorrect d. auto-catalytic RNA molecules. Correct e. DNA molecules whose information was transcribed to RNA and later translated in polypeptide