101 Biology DeSaix
1 April 2010
Name _______________
Print your name, last name first, and your PID number legibly on your answer sheet. Bubble in both below. Each answer is worth 2 points. Always choose one best answer and use only number 2 pencils to fill in your answers. Be sure to sign the pledge on your answer sheet. The last question will be used only if another question has to be deleted. Turn in your answer sheet in alphabetical order at the front of the room. Keep your test paper with answers to check against the key so that you will know what you have missed. The key will be posted after the test. Choose the one most appropriate answer for the next 5 questions. 1) control over enzyme activity 2) transcript processing 3) post-translational control 4) transcriptional control 5) transport control __4__ 1. influences the amount and kinds of mRNA copied from structural genes. __2__ 2. snipping out of transcript regions; chemical modification of transcript before it arrives at ribosome control. __5__ 3. nuclear envelope selectively regulates passage of transcripts. __1__ 4. for example, the interior environmental pH determines whether a protein can act as a cell catalyst \ __5__ 5. Which of these is the smallest unit upon which natural selection directly acts? 1) a species' gene frequency 2) a population's gene frequency 3) an individual's genome 4) an individual's genotype 5) an individual's phenotype __1__ 6. Using a restriction enzyme, you cut a plasmid into four pieces (A-D) with the following sizes. You run the pieces on a gel; what does the gel look like? A= 1287 nt B= 237 nt C= 980 nt D= 2970 nt
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A C B C C C A A D B B D D B A __2__ 7. How is the pedigree of an individual generally constructed? 1) by sequencing the genome of the individual. 2) by interviewing the individual regarding the sex and physical traits of his or her family members. 3) by sequencing the genes of the individual's parents. 4) by analyzing the genetic fingerprint of the individual and of all of his or her family members. __3__ 8. Which of the following is an application of recombinant DNA technology? 1) animal cloning 2) in vitro fertilization 3) rice plants that produce rice with Beta-carotene, a substance found in carrots 4) using bacteria to control the insect infestation of food crops. __1__ 9. In certain species crosses, such as that between the horse and the donkey, offspring are produced, but they are usually sterile. The most common explanation of this result is that: 1) the chromosomes of the two species differ too much to pair properly in meiosis. 2) the two species differ too much in behavior to be able to mate successfully. 3) embryological development in the two species are incompatible. 4) hormonal differences between the two species prevent proper development of the sex organs or gametes. 5) antibody formation in the offspring produced sterility. __4_ 10. The overall effect of gene flow is to: 1) create population bottlenecks. 2) increase the efficiency of natural selection. 3) create sexual barriers between populations. 4) decrease the difference between populations. 5) accelerate the process of speciation. __2_ 11. Which of these does NOT occur naturally: 1) A change in an individual's gene expression during its lifetime. 2) The occurrence of a mutation because it is needed for survival. 3) A greater number of mutations under some conditions than under others. 4) The environment determining which individuals of a population survive. 5) Gene flow between several populations of the same species. 1
_4_ 12. If you sampled the genetic characteristics of a large population and found that of the 50 loci analyzed there was very little if any variation, the most likely explanation would be that: 1) a uniform environment selected for these alleles 2) there has been a lack of migration and the genetic equilibrium stabilized the population 3) strong selection pressures eliminated alternative alleles 4) a bottleneck effect may have occurred in the past to reduce the variability in the population 5) a combination of low mutation rates and differential sexual selection produced these results. __3_ 13. The selective pressure behind Batesian mimicry is: 1) interspecific competition 2) intraspecific competition 3) predation 4) mutualism 5) commensalisms. __1_ 14. Suppose that the squirrels in the park near the Grand Canyon experienced an epidemic disease that killed 90 percent of them. What is a probable consequence of this event? 1) The survivors would exhibit an increase in resistance to the disease. 2) The genetic variability in the population would increase. 3) The mutation rate in genes for disease resistance would increase. 4) The pre-epidemic gene frequencies would be reestablished by genetic drift. 5) The survivors would migrate to a new, disease-free environment. __2_ 15. The presence of two or more allelic forms of a gene in a population is an example of: 1) polygenes 2) polymorphism 3) quantitative inheritance 4) a dihybrid cross. _2__ 16. A change in relative frequencies of alleles in the gene pool of population (no matter what the cause) is called: 1) genetic drift. 2) microevolution. 3) mutation. 4) diversifying selection. 5) directional selection. __4_ 17. Which of the following processes adds new alleles to the gene pool? 1) crossing over between genes 2) inversion 3) translocations 4) mutations 5) selection. _4__ 18. The evolutionary theory proposed by Charles Darwin was: 1) change in populations through time as a result of mutations. 2) the spontaneous generation of new organisms. 3) the passing on of genes from one generation to the next. 4) change in populations through time as a response to environmental change. 5) the development of characteristics by organisms in response to need. _4__ 19. A population of wild rats obeying the Hardy-Weinberger Law with respect to coat color would be expected to: 1) increase the proportion of dominant phenotypes. 2) increase the proportion of heterozygotes. 3) increase the proportion of homozygous recessives. 4) maintain a constant proportion of dominant to recessive genes. 5) eliminate heterozygosity. _1__ 20. If the frequency of the recessive allele is 30 percent, the frequency of the heterozygous carrier would be what percent? 1) 42 2) 9 3) 27 4) 60 5) 80. __4_ 21. In developing the theory of evolution, Darwin and Wallace were influenced by a particular essay. Which of the following include the author and content of that essay? 1) Lamarck Acquired characteristics 2) Hutchinson Niche principle 3) Mendel Classical genetics 4) Malthus Population growth 5) Bates wasps and bees. __3_ 22. An enzyme that recognizes the nucleotide sequence ATTGTCAAC wherever it occurs and splits a DNA molecule between the two adenines would be called a(n): 1) DNA polymerase. 2) DNA ligase. 3) restriction enzyme. 4) reverse transcriptase. 5) DNA transformase. _3__ 23. Your bone cells, muscle cells, and skin cells look different because: 1) different kinds of genes are present in each kind of cell. 2) they are present in different organs. 3) different genes are active in each kind of cell. 4) they contain different numbers of genes. 5) different mutations have occurred in each kind of cell __4_ 24. When plasmids are used to produce a desired protein: 1) the plasmids are inserted into the bacterial chromosome. 2) the plasmids multiply and produce the protein outside of the bacterium. 3) the bacterial chromosome is genetically engineered and the plasmid is used to help the bacterium replicate. 4) the desired gene is inserted into the plasmid and the plasmid is returned to the bacterium by transformation. 5) the bacterial genome and plasmid are inserted into the genome of the cell containing the desired gene (perhaps the cell of a plant or animal). _5__ 25. Four of the five answers listed below are aspects of the process known as gene splicing. Select the exception. 1) cloning cells 2) restriction enzymes 3) sticky ends 4) exposed base pairs 5) crossing over. _2__ 26. If you commit a crime, you need to make sure that you do not leave even the smallest speck of blood, hair, etc. from your body behind because if you do, the DNA in this material can be amplified by __________, subjected to genetic analysis, and used to identify you as the perpetrator of the crime. 1) ATP 2) PCR 3) blotting 4) RFLP 5) reverse transcriptase. 2
__3_ 27. Which of the following is not true about plasmids used to make recombinant DNA? 1) They may contain antibiotic resistance markers 2) They contain sites for restriction enzymes to cut 3) They are isolated from viruses 4)They are double stranded 5)They can self-replicate _3__ 28. ___ 28. Which cannot be used a template for PCR? 1) Blood sample from a patient 2) Plasmid isolated from bacteria 3) Purified hemoglobin protein 4) HIV virus )All can be used as template __4_ 29. Most differentiated cells retain: 1) only a tiny fraction of their original set of genes. 2) only a tiny fraction of their original set of genes but can regenerate lost genes as needed. 3) most, if not all, of their genes but lose the ability to express most of those genes. 4) most, if not all, of genes their and retain the ability to express those genes under certain circumstances. 5) none of the choices are correct. _2__ 30. What type of allele causes Huntington's disease? About how old are patients when the disease show up? 1) lethal recessive; 5 years old 2) lethal dominant; 40 years old 3) nonlethal recessive; 20 years old 4) nonlethal dominant; 25 years old 5) lethal dominant; before birth. _3__ 31. Which of the following is not an example of increased surface area that meets the needs of the cells of an organism? 1) Villi and microvilli waving in the intestine. 2) Interior membrane of the mitochondria. 3) Cnidarians exchanging materials with their environment through direct diffusion. 4) Pockets and pouches (alveoli) in the lungs. _1__ 32. Which of the following best expresses the concept of natural selection? 1) differential reproductive success based on inherited characteristics 2) inheritance of traits which were influenced by environment during the lifetime of parents (such as obesity from excess caloric intake) 3) organismal characteristics change because new characteristics are needed 4) each descendent being different than the parents 5) survival of the fittest. _5__ 33. DNA ligase is put to which of the following uses in genetic engineering? 1) to cause transformation of a bacterial cell. 2) to synthesize cDNA from mRNA. 3) to open up a plasmid so foreign DNA can be inserted 4) to get a plasmid into a bacterial host cell. 5) to join two DNA molecules together. __3_ 34. The feature of "sticky ends" that makes them especially useful in DNA recombination is their ability to: 1) bind to DNA and therefore activate transcription. 2) bind to DNA and thereby activate translation. 3) form base pairs with complementary single-stranded stretches of DNA. 4) allow plasmids to attach to the main bacterial chromosome. 5) insert a segment of DNA into a chromosome. __4_ 35. When lactose binds to the lac repressor of the bacterium Escherichia coli, 1) RNA polymerase cannot get access to the structural gene. 2) the repressor binds to the DNA. 3) RNA polymerase can bind to the lactose. 4) lactose is broken down. 5) structural genes strengthen the DNA. _2__ 36. What happens to the primary transcript before an mRNA molecule is translated? 1) It is copied onto tRNA. 2) Its introns are removed. 3) Its exons are broken down. 4) It unwinds a section of chromosome. 5) It is bound to a ribosome. _3__ 37. What might happen to a child with phenylketonuria (PKU) who eats a diet containing too much phenylalanine? 1) hemophilia 2) color blindness 3) mental retardation 4) albinism 5) none of the above. __3_ 38. If a male child has PKU, what can you say about his parents? 1) At least one parent has PKU 2) One parent carries the gene for PKU 3) Both parents carry the gene for PKU. 4) Only the mother has PKU. 5) The answer cannot be determined without more data. __5_ 39. In a population of bears, which would be considered the fittest? 1) the biggest bear 2) the bear having the largest number of mutations 3) the bear that blends in with its environment the best 4) the strongest, fiercest bear 5) the bear that leaves the most descendants. __2_ 40. Rabbits living farther north tend to have smaller ears. This is an example of: 1) speciation. 2) directional selection. 3) artificial selection. 4) heterozygote advantage. 5) genetic drift. _4__41. Which of these is not homeostatic? 1) negative feedback. 2) sweating when the temperature increases 3) producing more red blood cells when the oxygen level is low. 4) positive feedback. 5) converting glycogen to glucose during periods of low blood sugar. _2__ 42. Biologists have noticed that most human beings enjoy sex. How would they explain this, in evolutionary terms? 1) If sex were not enjoyable, the human species would have died out. 2) Early humans who enjoyed sex most had the most babies. 3) Only body structures evolve, not behavior, so enjoyment cannot evolve. 4) This was due to a random mutation, so it did not affect evolution. 5) Like most people, biologists are baffled by the phenomenon of sex. 3
_4__ 43. Which of the following would result in evolutionary adaptation of a mouse population to its environment? 1) Half the mice are killed by an avalanche. 2) A mutation for spotted fur occurs. 3) Several mice leave the area and mate with individuals elsewhere. 4) Mice with thicker fur best survive a cold winter. 5) Mice are most likely to mate with close neighbors. __2_ 44. Some critics of evolution believe that the theory of evolution is flawed because it is based on random changes--mutations. They say that a random change in an organism (or a car or a TV set) is likely to harm it, not make it function better. What logical statement could a defender of evolution make in reply to this criticism? 1) Fossils prove without a doubt that mutations drive evolution. 2) Mutation is random, but natural selection is not. 3) Mutation has little to do with evolution. 4) This is a weak spot in the theory that remains to be worked out. 5) Mutations are not actually random. _5__ 45. A zoologist found that in the population of frogs in MacGregor's pond, half the genes for skin color in the gene pool were alleles for green spots, and half the genes were alleles for brown spots. Which of the following could cause these proportions to change? 1) A drought shrinks the pond so that only five frogs remain. 2) Brown-spotted females prefer to mate with brown-spotted males. 3) Green-spotted frogs can hide more easily among the pond weeds. 4) Filling in a nearby pond causes those frogs to move to MacGregor's pond. 5) Any of the above could cause the proportions to change. __4_ 46. Each of us is part of the ongoing evolution of the human species. Which of the following occurrences would have the greatest impact on the future biological evolution of the human population? 1) You work out every day so that you stay physically fit and healthy. 2) A mutation occurs in one of your skin cells. 3) You move to Hawaii, the state with the longest life expectancy. 4) A mutation occurs in one of your sperm or egg cells. 5) You encourage your children to develop their intellectual abilities. __1_ 47. Imagine a scenario in which part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species? 1) Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. 2) The preferred food of the island birds is quite different from the diet of mainland birds. 3) Individuals from the different populations frequently direct courtship behavior toward members of the other population. 4) Hybrid offspring of matings between individuals from the two populations do not look like either parent. 5) The island birds all have red feathers, but the mainland birds have green feathers. __3_ 48. A new species can arise in a single generation ____________. 1) through geographical isolation. 2) in a very large population spread over a large area. 3) if a change in chromosome number creates a reproductive barrier. 4) if sexual selection occurs. 5) if adaptive radiation occurs. __3_ 49. Lake Malawi, in the African Rift Valley, is home to more than a hundred species of cichlid fishes, each with slightly different diets and habits. All these species probably evolved from a common ancestor, making them an example of __________. 1) stabilizing selection 2) hybrid breakdown 3) adaptive radiation 4) convergence 5) hybrid sterility. _3__ 50. Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should: 1) result in the extinction of one of the two parental species. 2) cause convergent evolution. 3) reinforce postzygotic barriers between horses and donkeys. 4) weaken the intrinsic reproductive barriers between horses and donkeys. 5) eventually result in the formation of a single species from the two parental species. _3__ 51. Two closely related populations of mice have been separated for a long period 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? 1) They interbreed freely and produce fertile hybrid offspring. 2) They no longer attempt to interbreed. 3) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations. 4) They remain separate in the extremes of their ranges but develop a hybrid zone in the area of overlap. 5) They interbreed in the region of overlap, but produce sterile offspring. 4