chapters-16-18-for-blog(2)
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chapters-16-18-for-blog(2)

Course Number: BIO 5, Spring 2009

College/University: UC Riverside

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Chapters 16-18 TEST Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____ 1. For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. This is because a. proteins have a greater...

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16-18 Chapters TEST Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____ 1. For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. This is because a. proteins have a greater variety of three-dimensional forms than does DNA. b. proteins have two different levels of structural organization; DNA has four. c. proteins are made of 20 amino acids and DNA is made of four nucleotides. d. Only A and C are correct. e. A, B, and C are correct. 2. In his transformation experiments, Griffith observed that a. mutant mice were resistant to bacterial infections. b. mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. c. mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic. d. infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains. e. mice infected with a pathogenic strain of bacteria can spread the infection to other mice. 3. What does transformation involve in bacteria? a. the creation of a strand of DNA from an RNA molecule b. the creation of a strand of RNA from a DNA molecule c. the infection of cells by a phage DNA molecule d. the type of semiconservative replication shown by DNA e. assimilation of external DNA into a cell 4. Avery and his colleagues purified various chemicals from pathogenic bacteria and showed that ____ was (were) the transforming agent. a. DNA b. protein c. lipids d. carbohydrates e. phage 5. Tobacco mosaic virus has RNA rather than DNA as its genetic material. In a hypothetical situation where RNA from a tobacco mosaic virus is mixed with proteins from a related DNA virus, the result could be a hybrid virus. If that virus were to infect a cell and reproduce, what would the resulting "offspring" viruses be like? a. tobacco mosaic virus b. the related DNA virus c. a hybrid: tobacco mosaic virus RNA and protein from the DNA virus d. a hybrid: tobacco mosaic virus protein and nucleic acid from the DNA virus e. a virus with a double helix made up of one strand of DNA complementary to a strand of RNA surrounded by viral protein 6. The following scientists made significant contributions to our understanding of the structure and function of DNA. Place the scientists' names in the correct chronological order, starting with the first scientist(s) to make a contribution. ____ ____ ____ ____ ____ I. II. III. IV. V. Avery, McCarty, and MacLeod Griffith Hershey and Chase Meselson and Stahl Watson and Crick ____ ____ ____ a. V, IV, II, I, III b. II, I, III, V, IV c. I, II, III, V, IV d. I, II, V, IV, III e. II, III, IV, V, I 7. After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. The best evidence that the ability to fluoresce is a heritable trait would be an observation that a. DNA passed from the heat-killed strain to the living strain. b. protein passed from the heat-killed strain to the living strain. c. the phosphorescence in the living strain is especially bright. d. descendants of the living cells are also phosphorescent. e. both DNA and protein passed from the heat-killed strain to the living strain. 8. In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? a. DNA does not contain sulfur, whereas protein does. b. DNA contains phosphorus, but protein does not. c. DNA contains nitrogen, whereas protein does not. d. A and B only e. A, B, and C 9. For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work? a. There is no radioactive isotope of nitrogen. b. Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long. c. Meselson and Stahl already did this experiment. d. Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive. e. Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins. Match the investigator(s) to the appropriate discovery of about the nature of genes. A. Frederick Griffith B. Alfred Hershey and Martha Chase C. Oswald Avery, Maclyn McCarty, and Colin MacLeod D. Erwin Chargaff E. Matthew Meselson and Franklin Stahl ____ 10. Chemicals from heat-killed S cells were purified. The chemicals were tested for the ability to transform live R cells. The transforming agent was found to be DNA. ____ 11. ____ 12. ____ 13. ____ 14. ____ 15. ____ 16. ____ 17. a. A b. B c. C d. D e. E Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacterial cells, and was therefore the genetic material. a. A b. B c. C d. D e. E In DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine. a. A b. B c. C d. D e. E When T2 phages infect bacteria and make more viruses in the presence of radioactive sulfur, what is the result? a. The viral DNA will be radioactive. b. The viral proteins will be radioactive. c. The bacterial DNA will be radioactive. d. both A and B e. both A and C Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately, what percentage of the nucleotides in this sample will be thymine? a. 12 b. 24 c. 31 d. 38 e. It cannot be determined from the information provided. Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that a. the relative proportion of each of the four bases differs from species to species. b. the human genome is more complex than that of other species. c. the amount of A is always equivalent to T, and C to G. d. both A and C e. both B and C All of the following can be determined directly from X-ray diffraction photographs of crystallized DNA except the a. diameter of the helix. b. helical shape of DNA. c. sequence of nucleotides. d. spacing of the nitrogenous bases along the helix. e. number of strands in a helix. The DNA double helix has a uniform diameter because ____, which have two rings, always pair with ____, which have one ring. a. purines; pyrimidines ____ 18. ____ 19. ____ 20. ____ 21. ____ 22. ____ 23. ____ 24. b. pyrimidines; purines c. deoxyribose sugars; ribose sugars d. ribose sugars; deoxyribose sugars e. nucleotides; nucleoside triphosphates What kind of chemical bond is found between paired bases of the DNA double helix? a. hydrogen b. ionic c. covalent d. sulfhydryl e. phosphate Which of the following statements does not apply to the Watson and Crick model of DNA? a. The two strands of the DNA form a double helix. b. The distance between the strands of the helix is uniform. c. The framework of the helix consists of sugar-phosphate units of the nucleotides. d. The two strands of the helix are held together by covalent bonds. e. The purines form hydrogen bonds with pyrimidines. It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in its a. sequence of bases. b. phosphate-sugar backbones. c. complementary pairing of bases. d. side groups of nitrogenous bases. e. different five-carbon sugars. In an analysis of the nucleotide composition of DNA, which of the following is true? a. A = C b. A = G and C = T c. A + C = G + T d. G + A = T + C e. both C and D Which of the following statements is false when comparing prokaryotes with eukaryotes? a. The prokaryotic chromosome is circular, whereas eukaryotic chromosomes are linear. b. Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. c. The rate of elongation during DNA replication is higher in prokaryotes than in eukaryotes. d. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not. e. Eukaryotes have telomeres, and prokaryotes do not. The strands that make up DNA are antiparallel. This means that a. the twisting nature of DNA creates nonparallel strands. b. the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. c. base pairings create unequal spacing between the two DNA strands. d. one strand is positively charged and the other is negatively charged. e. one strand contains only purines and the other contains only pyrimidines. Suppose one were provided with an actively dividing culture of E. coli bacteria to which radioactive thymine had been added. What would happen if a cell replicated once in the presence of this radioactive base? a. One of the daughter cells, but not the other, would have radioactive DNA. b. Neither of the two daughter cells would be radioactive. c. All four bases of the DNA would be radioactive. d. Radioactive thymine would pair with nonradioactive guanine. e. DNA in both daughter cells would be radioactive. Use the figure below to answer the following questions. ____ 25. In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen (15N) and then transferred them to a medium containing 14N. Which of the results in the figure above would be expected after one DNA replication in the presence of 14N? a. A b. B c. C d. D e. E ____ 26. A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in 15N medium for several generations and then transfer them to 14N medium. Which pattern in the figure above would you expect if the DNA was replicated in a conservative manner? a. A b. B c. C d. D e. E ____ 27. Which enzyme catalyzes the elongation of a DNA strand in the 5' 3' direction? a. primase b. DNA ligase c. DNA polymerase d. topoisomerase e. helicase ____ 28. What determines the nucleotide sequence of the newly synthesized strand during DNA replication? a. the particular DNA polymerase catalyzing the reaction b. the relative amounts of the four nucleoside triphosphates in the cell c. the nucleotide sequence of the template strand d. the primase used in the reaction e. both A and D ____ 29. What is the function of DNA polymerase? a. to unwind the DNA helix during replication b. to seal together the broken ends of DNA strands c. to add nucleotides to the end of a growing DNA strand d. to degrade damaged DNA molecules e. to rejoin the two DNA strands (one new and one old) after replication ____ 30. Which of the following is least related to the others on the list? a. Okazaki fragments b. replication fork c. telomerase d. DNA polymerase e. semiconservative model ____ 31. You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent a. leading strands and Okazaki fragments. b. lagging strands and Okazaki fragments. c. Okazaki fragments and RNA primers. d. leading strands and RNA primers. e. RNA primers and mitochondrial DNA. Refer to the list of enzymes below to answer the following questions. The answers may be used once, more than once, or not at all. A. helicase B. nuclease C. ligase D. DNA polymerase I E. primase ____ 32. removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments a. A b. B c. C d. D e. E ____ 33. separates the DNA strands during replication a. A b. B c. C d. D e. E ____ 34. covalently connects segments of DNA a. A b. B c. C d. D e. E ____ 35. synthesizes short segments of RNA a. A b. B c. C d. D e. E ____ 36. DNA-cutting enzymes used in the repair of DNA damage a. A b. B c. C d. D e. E ____ 37. The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that a. the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose. b. the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups. c. ATP contains three high-energy bonds; the nucleoside triphosphates have two. d. ATP is found only in human cells; the nucleoside triphosphates are found in all animal and plant cells. e. triphosphate monomers are active in the nucleoside triphosphates, but not in ATP. ____ 38. The Y-shaped structure where the DNA double helix is actively unwound during DNA replication is called the a. replication fork. b. replication Y. c. elongation junction. d. unwinding point. e. Y junction. ____ 39. The leading and the lagging strands differ in that a. the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction. b. the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end. c. the leading strand is synthesized continuously, whereas the lagging strand is synthesized in short fragments that are ultimately stitched together. d. both A and B e. both A and C ____ 40. Which of the following best describes the addition of nucleotides to a growing DNA chain? a. A nucleoside triphosphate is added to the 5' end of the DNA, releasing a molecule of pyrophosphate. b. A nucleoside triphosphate is added to the 3' end of the DNA, releasing a molecule of pyrophosphate. c. A nucleoside diphosphate is added to the 5' end of the DNA, releasing a molecule of phosphate. d. A nucleoside diphosphate is added to the 3' end of the DNA, releasing a molecule of phosphate. e. A nucleoside monophosphate is added to the 3' end of the DNA. ____ 41. A new DNA strand elongates only in the 5' to 3' direction because a. DNA polymerase begins adding nucleotides at the 5' end of the template. b. Okazaki fragments prevent elongation in the 3' to 5' direction. c. the polarity of the DNA molecule prevents addition of nucleotides at the 3' end. d. replication must progress toward the replication fork. e. DNA polymerase can only add nucleotides to the free 3' end. ____ 42. Replicating the lagging strand of DNA-that is, adding bases in the 3' 5' direction-utilizes which of the following? a. DNA ligase b. RNA primers c. Okazaki fragments d. A and B only ____ 43. ____ 44. ____ 45. ____ 46. ____ 47. ____ 48. ____ 49. ____ 50. e. A, B, and C What kind of molecule or substance is the primer that is used to initiate the synthesis of a new DNA strand? a. RNA b. DNA c. protein d. phosphate e. sulfur What is the function of topoisomerase? a. relieving strain in the DNA ahead of the replication fork b. elongation of new DNA at a replication fork by addition of nucleotides to the existing chain c. the addition of methyl groups to bases of DNA d. unwinding of the double helix e. stabilizing single-stranded DNA at the replication fork What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? a. synthesize RNA nucleotides to make a primer b. catalyze the lengthening of telomeres c. join Okazaki fragments together d. unwind the parental double helix e. stabilize the unwound parental DNA All of the following are functions of DNA polymerase in DNA replication except a. covalently adding nucleotides to the new strands. b. proofreading each added nucleotide for correct base pairing. c. replacing RNA primers with DNA. d. initiating a polynucleotide strand. e. none of the above Which of the following help to hold the DNA strands apart while they are being replicated? a. primase b. ligase c. DNA polymerase d. single-strand binding proteins e. exonuclease Which of these mechanisms ensures that the DNA sequence in the genome remains accurate? a. proofreading during DNA replication b. mismatch repair c. excision repair d. complementary base pairing during DNA replication e. all of the above Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight because their cells have an impaired ability to a. replicate DNA. b. undergo mitosis. c. exchange DNA with other cells. d. repair thymine dimers. e. recombine homologous chromosomes during meiosis. Which of the following is analogous to telomeres? a. the pull tab on a soft drink can b. the two ends of a shoelace c. the central spindle that a CD fits around while in the case d. the mechanism of a zipper that allows the separated parts to be joined e. the correct letters used to replace errors in a document after they have been deleted in a word processor ____ 51. A eukaryotic cell lacking telomerase would a. have a high probability of becoming cancerous. b. produce Okazaki fragments. c. be unable to repair thymine dimers. d. undergo a reduction in chromosome length. e. be highly sensitive to sunlight. ____ 52. Which of the following statements about telomeres is correct? a. They contain multiple copies of a short RNA sequence. b. They are present at the ends of eukaryotic chromosomes. c. They can be extended by an enzyme called telomerase. d. both A and B e. both B and C ____ 53. Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because a. genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes. b. enzymes are made of DNA, and affected individuals lack DNA polymerase. c. many metabolic enzymes use DNA as a cofactor, and affected individuals have mutations that prevent their enzymes from interacting efficiently with DNA. d. certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors. e. metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies. The following questions refer to the following simple metabolic pathway: enzyme A enzyme B ____ 54. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway? a. 0 b. 1 c. 2 d. 3 e. It cannot be determined from the pathway. ____ 55. A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation? a. an accumulation of A and no production of B and C b. an accumulation of A and B and no production of C c. an accumulation of B and no production of A and C d. an accumulation of B and C and no production of A e. an accumulation of C and no production of A and B ____ 56. If A, B, and C are all required for growth, a strain that is mutant for the gene encoding enzyme A would be able to grow on which of the following media? a. minimal medium b. minimal medium supplemented with nutrient "A" c. minimal medium supplemented with nutrient "B" d. minimal medium supplemented with nutrient "C" e. Answers C and D are correct. ____ 57. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be capable of growing on which of the following media? a. minimal medium b. minimal medium supplemented with "A" c. minimal medium supplemented with "B" d. minimal medium supplemented with "C" e. answers B and C ____ 58. We now know that the one gene-one enzyme hypothesis is not entirely accurate because a. many genes code for proteins that are not enzymes. b. a single gene codes for a single polypeptide chain, and many enzymes are made up of more than one polypeptide chain. c. many genes code for RNA molecules that have no enzymatic activity. d. A and B only e. A, B, and C ____ 59. Which of the following represents a similarity between RNA and DNA? a. Both are double-stranded. b. the presence of uracil c. the presence of an OH group on the 2' carbon of the sugar d. nucleotides consisting of a phosphate, sugar, and nitrogenous base e. Both are found exclusively in the nucleus. ____ 60. The nitrogenous base adenine is found in all members of which group? a. proteins, triglycerides, and testosterone b. proteins, ATP, and DNA c. ATP, RNA, and DNA d. alpha glucose, ATP, and DNA e. proteins, carbohydrates, and ATP ____ 61. Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because a. RNA is much more stable than DNA. b. RNA acts as an expendable copy of the genetic material, allowing the DNA to serve as a permanent, pristine repository of the genetic material. c. many mRNA molecules can be transcribed from a single gene, increasing the potential rate of gene expression. d. B and C only e. A, B, and C ____ 62. If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codon size in a genetic system with four different nucleotides? a. 1 b. 2 c. 3 d. 4 e. 12 ____ 63. An extraterrestrial life form is discovered. It has a genetic code much like that of organisms on Earth except that there are five different DNA bases instead of four and the base sequences are translated as doublets instead of triplets. How many different amino acids could be accommodated by this genetic code? a. 5 b. 10 c. 25 d. 64 e. 32 ____ 64. The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. The resulting artificial mRNA molecule would have ____ possible different codons if the code involved twobase sequences and ____ possible different codons if the code involved three-base sequences. a. 2; 3 b. 2; 4 c. 4; 8 d. 4; 16 e. 16; 64 ____ 65. A particular triplet of bases in the template strand of DNA is AGT. The corresponding codon for the mRNA transcribed is a. AGT. b. UGA. c. TCA. d. ACU. e. either UCA or TCA, depending on wobble in the first base Use the table of condons below to answer the following questions. ____ 66. A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be a. 5' TTG-CTA-CAG-TAG 3'. b. 3' AAC-GAC-GUC-AUA 5'. c. 5' AUG-CTG-CAG-TAT 3'. d. 3' AAA-AAT-ATA-ACA 5'. e. 3' AAA-GAA-TAA-CAA 5'. ____ 67. What amino acid sequence will be generated, based on the following mRNA codon sequence? 5'AUG-UCU-UCG-UUA-UCC-UUG a. met-arg-glu-arg-glu-arg b. met-glu-arg-arg-gln-leu c. met-ser-leu-ser-leu-ser d. met-ser-ser-leu-ser-leu e. met-leu-phe-arg-glu-glu ____ 68. A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA codes for this peptide? a. 3' UUU-CCC-AAA-GGG-UUU-CCC b. 3' AUG-AAA-GGG-TTT-CCC-AAA-GGG c. 5' TTT-CCC-AAA-GGG-TTT-CCC d. 5' GGG-AAA-TTT-AAA-CCC-ACT-GGG e. 5' ACT-TAC-CAT-AAA-CAT-TAC-UGA ____ 69. What is the sequence of a peptide based on the mRNA sequence 5' UUUUCUUAUUGUCUU 3' ? a. leu-cys-tyr-ser-phe b. cyc-phe-tyr-cys-leu c. phe-leu-ile-met-val d. leu-pro-asp-lys-gly e. phe-ser-tyr-cys-leu ____ 70. Suppose the following DNA sequence was mutated from 3' AGAGAGAGAGAGAGAGAG 5' to 3' AGAAGAGAGATCGAGAGA 5'. What amino acid sequence will be generated based on this mutated DNA? a. arg-glu-arg-glu-arg-glu b. glu-arg-glu-leu-leu-leu c. ser-leu-ser-leu-ser-leu d. ser-ser-leu e. leu-phe-arg-glu-glu-glu ____ 71. A particular eukaryotic protein is 300 amino acids long. Which of the following could be the maximum number of nucleotides in the DNA that codes for the amino acids in this protein? a. 3 b. 100 c. 300 d. 900 e. 1,800 ____ 72. A codon a. consists of two nucleotides. b. may code for the same amino acid as another codon. c. consists of discrete amino acid regions. d. catalyzes RNA synthesis. e. is found in all eukaryotes, but not in prokaryotes. ____ 73. If the triplet CCC codes for the amino acid proline in bacteria, then in plants CCC should code for a. leucine. ____ 74. ____ 75. ____ 76. ____ 77. ____ 78. ____ 79. ____ 80. b. valine. c. cystine. d. phenylalanine. e. proline. The genetic code is essentially the same for all organisms. From this, one can logically assume all of the following except a. a gene from an organism could theoretically be expressed by any other organism. b. all organisms have a common ancestor. c. DNA was the first genetic material. d. the same codons in different organisms usually translate into the same amino acids. e. different organisms have the same number of different types of amino acids. Which of the following is true for both prokaryotic and eukaryotic gene expression? a. After transcription, a 3' poly-A tail and a 5' cap are added to mRNA. b. Translation of mRNA can begin before transcription is complete. c. RNA polymerase binds to the promoter region to begin transcription. d. mRNA is synthesized in the 3' ? 5' direction. e. The mRNA transcript is the exact complement of the gene from which it was copied. Which of the following are transcribed from DNA? a. protein b. exons c. rRNA d. B and C only e. A, B, and C RNA polymerase and DNA polymerase differ in that a. RNA polymerase uses RNA as a template, and DNA polymerase uses a DNA template. b. RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to doublestranded DNA. c. RNA polymerase is much more accurate than DNA polymerase. d. RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis. e. RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA. Which of the following is not a part of the eukaryotic transcription initiation complex? a. promoter b. RNA polymerase c. transcription factors d. snRNP e. TATA box Which of the following is least related to the other items? a. translation b. TATA box c. transcription d. template strand e. RNA polymerase II Which of the following statements best describes the termination of transcription in prokaryotes? a. RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. b. RNA polymerase transcribes through the terminator sequence, causing the polymerase to ____ 81. ____ 82. ____ 83. ____ 84. ____ 85. ____ 86. ____ 87. fall off the DNA and release the transcript. c. RNA polymerase transcribes through an intron, and the snRNPs cause the polymerase to let go of the transcript. d. Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome. e. RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA. RNA polymerase moves along the template strand of DNA in the ____ direction, and adds nucleotides to the ____ end of the growing transcript. a. 3' to 5'; 5' b. 3' to 5'; 3' c. 5' to 3'; 5' d. 5' to 3'; 3' All of the following are found in prokaryotic mRNA except a. the AUG codon. b. the UGA codon. c. introns. d. uracil. e. cytosine. Which of the following helps to stabilize mRNA by inhibiting its degradation? a. TATA box b. spliceosomes c. 5' cap d. poly-A tail e. both C and D What is a ribozyme? a. An enzyme that uses RNA as a substrate b. An enzyme made up of RNA c. An enzyme that catalyzes the association between the large and small ribosomal subunits d. An enzyme that synthesizes RNA as part of the transcription process e. An enzyme that synthesizes RNA primers during DNA replication What are the coding segments of a stretch of eukaryotic DNA called? a. introns b. exons c. codons d. replicons e. transposons A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of 400 amino acids. This is best explained by the fact that a. many noncoding nucleotides are present in mRNA. b. there is redundancy and ambiguity in the genetic code. c. many nucleotides are needed to code for each amino acid. d. nucleotides break off and are lost during the transcription process. e. there are termination exons near the beginning of mRNA. Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes a. excision of introns. b. fusion into circular forms known as plasmids. c. linkage to histone molecules. d. union with ribosomes. ____ 88. ____ 89. ____ 90. ____ 91. ____ 92. ____ 93. ____ 94. ____ 95. e. fusion with other newly transcribed mRNA. Introns are significant to biological evolution because a. their presence allows exons to be moved around more easily, creating proteins with new combinations of functional domains. b. they protect the mRNA from degeneration. c. they are translated into essential amino acids. d. they maintain the genetic code by preventing incorrect DNA base pairings. e. they correct enzymatic alterations DNA of bases. A mutation in which of the following parts of a gene is likely to be most damaging to a cell? a. intron b. exon c. 5' UTR d. 3' UTR e. All would be equally damaging. Which of the following is (are) true of snRNPs? a. They are made up of both protein and RNA. b. They bind to splice sites at each end of the intron. c. They join together to form a large structure called the spliceosome. d. Only A and C are true. e. A, B, and C are true During splicing, which molecular component of the spliceosome catalyzes the excision reaction? a. RNA b. DNA c. protein d. lipid e. sugar Alternative RNA splicing a. is a mechanism for increasing the rate of transcription. b. can allow the production of proteins of dramatically different sizes from a single mRNA. c. can allow the production of proteins of dramatically different amino acid sequences from a single mRNA. d. B and C only e. A, B, and C Which of the following is least related to the other items? a. snRNP b. triplet code c. wobble d. tRNA e. anticodon All of the following are directly involved in translation except a. mRNA. b. tRNA. c. ribosomes. d. DNA. e. aminoacyl-tRNA synthetase enzymes. A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is a. TTT. b. UUA. c. UUU. d. AAA. e. either UAA or TAA, depending on first base wobble. ____ 96. Accuracy in the translation of mRNA into the primary structure of a protein depends on specificity in the a. binding of ribosomes to mRNA. b. shape of the A and P sites of ribosomes. c. bonding of the anticodon to the codon. d. attachment of amino acids to tRNAs. e. both C and D ____ 97. What is an anticodon part of? a. DNA b. tRNA c. mRNA d. a ribosome e. an activating enzyme ____ 98. A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (mRNA). The following activated transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. tRNA Anticodon GGC CGU UGC CCG ACG CGG Amino Acid Proline Alanine Threonine Glycine Cysteine Alanine The dipeptide that will form will be a. cysteine-alanine. b. proline-threonine. c. glycine-cysteine. d. alanine-alanine. e. threonine-glycine. ____ 99. What type of bonding is responsible for maintaining the shape of the tRNA molecule? a. covalent bonding between sulfur atoms b. ionic bonding between phosphates c. hydrogen bonding between base pairs d. van der Waals interactions between hydrogen atoms e. peptide bonding between amino acids ____ 100. The figure below represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid? a. UGG b. GUG c. GUA d. UUC e. CAU ____ 101. A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of a phenylalanine. The consequence of this for the cell will be that a. none of the proteins in the cell will contain phenylalanine. b. proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. c. the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysinespecifying anticodons. d. the ribosome will skip a codon every time a UUU is encountered. e. None of the above will occur; the cell will recognize the error and destroy the tRNA. ____ 102. There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that a. some tRNAs have anticodons that recognize two or more different codons. b. the rules for base pairing between the third base of a codon and tRNA are flexible. c. many codons are never used, so the tRNAs that recognize them are dispensable. d. A and B only e. A, B, and C ____ 103. What are ribosomes composed of? a. rRNA only b. proteins only c. both rRNA and protein ____ 104. ____ 105. ____ 106. ____ 107. ____ 108. ____ 109. ____ 110. d. mRNA, rRNA, and protein e. mRNA, tRNA, rRNA, and protein Where is eukaryotic ribosomal RNA transcribed? a. the Golgi apparatus b. ribosomes c. the nucleolus d. X chromosomes e. prokaryotic cells only What is the most abundant type of RNA? a. mRNA b. tRNA c. rRNA d. pre-mRNA e. hnRNA The function of the ribosome in polypeptide synthesis is to a. hold mRNA and tRNAs together. b. catalyze the addition of amino acids from tRNAs to the growing polypeptide chain. c. move along the mRNA and eject tRNAs during the translocation process. d. A and B only e. A, B, and C From the following list, which is the first event in translation in eukaryotes? a. elongation of the polypeptide b. base pairing of activated methionine-tRNA to AUG of the messenger RNA c. binding of the larger ribosomal subunit to smaller ribosomal subunits d. covalent bonding between the first two amino acids e. Both B and D occur simultaneously. Choose the answer that has these events of protein synthesis in the proper sequence. 1. An aminoacyl-tRNA binds to the A site. 2. A peptide bond forms between the new amino acid and a polypeptide chain. 3. tRNA leaves the P site, and the P site remains vacant. 4. A small ribosomal subunit binds with mRNA. 5. tRNA translocates to the P site. a. 1, 3, 2, 4, 5 b. 4, 1, 2, 5, 3 c. 5, 4, 3, 2, 1 d. 4, 1, 3, 2, 5 e. 2, 4, 5, 1, 3 Which of the following is not directly involved in the process of translation? a. ligase b. tRNA c. rRNA d. mRNA e. aminoacyl-tRNA synthetase Which of the following components are present upon the completion of translation initiation? a. small ribosomal subunit b. large ribosomal subunit c. initiator tRNA d. A and C only e. A, B, and C ____ 111. During translation, chain elongation continues until what happens? a. No further amino acids are needed by the cell. b. All tRNAs are empty. c. The polypeptide is long enough. d. A stop codon is encountered. e. The ribosomes run off the end of mRNA. ____ 112. As a ribosome translocates along an mRNA molecule by one codon, which of the following occurs? a. The tRNA that was in the A site moves into the P site. b. The tRNA that was in the P site moves into the A site. c. The tRNA that was in the P site moves to the E site and is released. d. The tRNA that was in the A site departs from the ribosome. e. Both A and C are correct. ____ 113. Which of the following does not occur during the termination phase of translation? a. A termination codon causes the A site to accept a release factor. b. The newly formed polypeptide is released. c. A tRNA with the next amino acid enters the P site. d. The two ribosomal subunits separate. e. Translation stops. ____ 114. What are polyribosomes? a. groups of ribosomes reading a single mRNA simultaneously b. ribosomes containing more than two subunits c. multiple copies of ribosomes associated with giant chromosomes d. aggregations of vesicles containing ribosomal RNA e. ribosomes associated with more than one tRNA ____ 115. What is one function of a signal peptide? a. to direct an mRNA molecule into the cisternal space of the ER b. to bind RNA polymerase to DNA and initiate transcription c. to terminate translation of the messenger RNA d. to translocate polypeptides across the ER membrane e. to signal the initiation of transcription ____ 116. When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by a. a specific characteristic of the ribosome itself, which distinguishes free ribosomes from bound ribosomes. b. a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane. c. moving through a specialized channel of the nucleus. d. a chemical signal given off by the ER. e. a signal sequence of RNA that precedes the start codon of the message. ____ 117. Which of the following is least related to the other items? a. exons b. introns c. RNA splicing d. signal-recognition particles (SRPs) e. mRNA ____ 118. Which of the following is not related to ribosomal activity? a. A site b. spliceosome c. codon recognition d. peptide bond formation ____ 119. ____ 120. ____ 121. ____ 122. ____ 123. e. P site When does translation begin in prokaryotic cells? a. after a transcription initiation complex has been formed b. during transcription c. after the 5' caps are converted to mRNA d. once the pre-mRNA has been converted to mRNA e. as soon as the DNA introns are removed from the template Which of the following is (are) true about RNA? a. snoRNA aids in processing pre-rRNA transcripts in the nucleolus. b. SRP RNA is an essential component of spliceosomes. c. It has functional groups that allow it to act as a catalyst (ribozyme). d. Only A and C are true. e. A, B, and C are true. Which of the following statements are true about protein synthesis in prokaryotes? a. Translation can begin while transcription is still in progress. b. Extensive RNA processing is required before prokaryotic transcripts can be translated. c. Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. d. Only A and B are true. e. A, B, and C are true. Of the following types of mutations, which one is likely to be the most common? a. point mutation b. missense mutation c. base-pair substitution d. nonsense mutation e. frameshift mutation What is the effect of a nonsense mutation in a gene? a. It changes an amino acid in the encoded protein. b. It has no effect on the amino acid sequence of the encoded protein. c. It introduces a stop codon into the mRNA. d. It alters the reading frame of the mRNA. e. It prevents introns from being expressed. Each of the following is a modification of the sentence THECATATETHERAT. A.THERATATETHECAT B. THETACATETHERAT C. THECATARETHERAT D. THECATATTHERAT E. CATATETHERAT ____ 124. Which of the above is analogous to a frameshift mutation? a. A b. B c. C d. D e. E ____ 125. Which of the above is analogous to a single substitution mutation? a. A ____ 126. ____ 127. ____ 128. ____ 129. ____ 130. ____ 131. ____ 132. b. B c. C d. D e. E Sickle-cell disease is probably the result of which kind of mutation? a. point b. frameshift c. nonsense d. nondisjunction e. both B and D A frameshift mutation could result from a. a base insertion only. b. a base deletion only. c. a base substitution only. d. deletion of three consecutive bases. e. either an insertion or a deletion of a base. Which of the following DNA mutations is the most likely to be damaging to the protein it specifies? a. a base-pair deletion b. a codon substitution c. a substitution in the last base of a codon d. a codon deletion e. a point mutation Which point mutation would be most likely to have a catastrophic effect on the functioning of a protein? a. a base substitution b. a base deletion near the start of a gene c. a base deletion near the end of the coding sequence, but not in the terminator codon d. deletion of three bases near the start of the coding sequence, but not in the initiator codon e. a base insertion near the end of the coding sequence, but not in the terminator codon Which of the following is (are) true about viruses? a. Viruses are classified below the cellular level of biological organization. b. A single virus particle contains both DNA and RNA. c. Even small virus particles are visible with light microscopes. d. Only A and B are true. e. A, B, and C are true. Which of the following is not a reason scientists suspected that something other than bacteria was the cause of tobacco mosaic disease? a. Passing infectious sap through a fine filter failed to remove the infectious agent. b. Treating infectious sap with alcohol failed to remove the infectious agent. c. No cells could be seen in the infectious sap using a light microscope. d. The infectious agent in the sap could reproduce, as its ability to cause disease was undiluted even after many transfers from plant to plant. e. The infectious agent could not be cultivated on nutrient media in petri dishes or in test tubes. A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur? a. The plants would develop some but not all of the symptoms of the TMV infection. b. The plants would develop symptoms typically produced by viroids. c. The plants would develop the typical symptoms of TMV infection. ____ 133. ____ 134. ____ 135. ____ 136. ____ 137. ____ 138. ____ 139. d. The plants would not show any disease symptoms. e. The plants would become infected, but the sap from these plants would be unable to infect other plants. Which of the following is a characteristic of all viruses? a. a nucleic acid genome b. a protein capsid c. a viral envelope d. A and B only e. A, B, and C Viral genomes can consist of any of the following except a. double-stranded DNA. b. double-stranded RNA. c. single-stranded DNA. d. single-stranded RNA. e. helical capsomeres. The host range of a virus is determined by a. the proteins on its surface. b. whether its nucleic acid is DNA or RNA. c. the proteins on the surface of the host cell. d. the enzymes produced by the virus before it infects the cell. e. both A and C Viruses are referred to as obligate parasites because a. they cannot reproduce outside of a host cell. b. viral DNA always inserts itself into host DNA. c. they invariably kill any cell they infect. d. they can incorporate nucleic acids from other viruses. e. they must use enzymes encoded by the virus itself. Which of the following is characteristic of the lytic cycle? a. Many bacterial cells containing viral DNA are produced. b. Viral DNA is incorporated into the host genome. c. The viral genome replicates without destroying the host. d. A large number of phages are released at a time. e. The virus-host relationship usually lasts for generations. Bacteriophage DNA that have become integrated into the host cell chromosome are called a. intemperate bacteriophages. b. transposons. c. prophages. d. T-even phages. e. plasmids. Which of the following statements about the lysogenic cycle of lambda ( . phage is incorrect? a. After infection the viral genes immediately turn the host cell into a lambda-producing factory, and the host cell then lyses. b. Most of the prophage genes are silenced by the product of a particular prophage gene. c. The phage genome replicates along with the host genome. d. Certain environmental triggers can cause the phage to exit the host genome, switching from the lysogenic to the lytic cycle. e. The phage DNA is incorporated by genetic recombination (crossing over. into a specific site on the host cell's DNA. ____ 140. Virulent phages undergo a(n) ____ life cycle, whereas temperate phages are capable of undergoing a(n) ____ cycle. a. infective; retroviral b. lysogenic; lytic c. lytic; lysogenic d. retroviral; infective e. infective; benign ____ 141. What is the function of the single-stranded RNA in certain animal viruses? a. It can serve directly as mRNA. b. It can serve as a template for mRNA synthesis. c. It can serve as a template for DNA synthesis. d. Only A and C are correct. e. A, B, and C are correct. ____ 142. Viruses with single-stranded RNA that acts as a template for DNA synthesis are known as a. retroviruses. b. proviruses. c. viroids. d. bacteriophages. e. lytic phages. ____ 143. What is the function of reverse transcriptase in retroviruses? a. It hydrolyzes the host cell's DNA. b. It uses viral RNA as a template for DNA synthesis. c. It converts host cell RNA into viral DNA. d. It translates viral RNA into proteins. e. It uses viral RNA as a template for making complementary RNA strands. ____ 144. The membrane making up the viral envelope can come from a. the virus itself, using enzymes encoded by the virus. b. the nuclear membrane of an infected cell. c. the plasma membrane of an infected cell. d. both A and B e. both B and C ____ 145. Viral envelopes contain proteins with covalently attached carbohydrate groups called a. glycoproteins. b. proteosugars. c. carbopeptides. d. peptidocarbs. e. carboproteins. ____ 146. The simplest infectious biological systems are a. bacteria. b. viruses. c. viroids. d. both A and B e. both B and C ____ 147. Which of the following is a true statement? a. Viruses are uncommon. b. Viruses can cause diarrhea, colds, and measles. c. All viruses have a similar capsid and membranous envelope. d. All viruses contain the nucleic acid RNA. e. Viruses only invade animal cells. ____ 148. Which of the following can be effective against viral diseases? a. vaccination b. nucleoside analogs that inhibit DNA synthesis c. antibiotics d. A and B only e. A, B, and C ____ 149. RNA viruses appear to have higher rates of mutation because a. RNA nucleotides are more unstable than DNA nucleotides. b. replication of their genomes does not involve the proofreading steps of DNA replication. c. RNA viruses replicate faster. d. RNA viruses can incorporate a variety of nonstandard bases. e. RNA viruses are more sensitive to mutagens. Refer to the treatments listed below to answer the following questions. You isolate an infectious substance that is capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, viroid, or prion. You have four methods at your disposal that you can use to analyze the substance in order to determine the nature of the infectious agent. I. II. III. IV. treating the substance with nucleases that destroy all nucleic acids and then determining whether it is still infectious filtering the substance to remove all elements smaller than what can be easily seen under a light microscope culturing the substance by itself on nutritive medium, away from any plant cells treating the sample with proteases that digest all proteins and then determining whether it is still infectious ____ 150. Which treatment could definitively determine whether or not the component is a viroid? a. I b. II c. III d. IV e. first II and then III ____ 151. If you already knew that the infectious agent was either bacterial or viral, which treatment would allow you to distinguish between these two possibilities? a. I b. II c. III d. IV e. either II or IV ____ 152. Which treatment would you use to determine if the agent is a prion? a. I only b. II only c. III only d. IV only e. either I or IV ____ 153. Which of the following contributes to the emergence of viral disease? a. production of new virus strains through mutation b. spread of existing virus from one host species to another c. transformation from lytic to lysogenic activity ____ 154. ____ 155. ____ 156. ____ 157. ____ 158. ____ 159. d. A and B only e. A, B, and C Which of the following is true of plant virus infections? a. They can be controlled by the use of antibiotics. b. They are spread throughout a plant by passing through the plasmodesmata. c. They have little effect on plant growth. d. Only A and B are correct. e. A, B, and C are correct. Which of the following represents a difference between viruses and viroids? a. Viruses infect many types of cells, whereas viroids infect only prokaryotic cells. b. Viruses have capsids composed of protein, whereas viroids have no capsids. c. Viruses contain introns; viroids have only exons. d. Viruses always have genomes composed of DNA, whereas viroids always have genomes composed of RNA. e. Viruses cannot pass through plasmodesmata; viroids can. The difference between vertical and horizontal transmission of plant viruses is that a. vertical transmission refers to the transmission of a virus from a parent plant to its progeny, and horizontal transmission refers to one plant spreading the virus to another plant. b. vertical transmission refers to the spread of viruses from upper leaves to lower leaves of the plant, and horizontal transmission refers to the spread of a virus among leaves at the same general level. c. vertical transmission refers to the spread of viruses from trees and tall plants to bushes and other smaller plants, and horizontal transmission refers to the spread of viruses among plants of similar size. d. vertical transmission refers to the transfer of DNA from one type of plant virus to another, and horizontal transmission refers to the exchange of DNA between two plant viruses of the same type. e. vertical transmission refers to the transfer of DNA from a plant of one species to a plant of a different species, and horizontal transmission refers to the spread of viruses among plants of the same species. What are prions? a. misfolded versions of normal brain protein b. tiny molecules of RNA that infect plants c. viral DNA that has had to attach itself to the host genome d. viruses that invade bacteria e. a mobile segment of DNA Most molecular biologists think that viruses originated from fragments of cellular nucleic acid. Which of the following observations supports this theory? a. Viruses contain either DNA or RNA. b. Viruses are enclosed in protein capsids rather than plasma membranes. c. Viruses can reproduce only inside host cells. d. Viruses can infect both prokaryotic and eukaryotic cells. e. Viral genomes are usually more similar to the genome of the host cell than to the genomes of viruses that infect other cell types. Reproduction in bacteria requires a. the production of a mitotic spindle. b. a plasmid. c. cyclic AMP. d. replication of DNA. e. both B and D ____ 160. What is the most common source of genetic diversity in a bacterial colony? a. transposons b. plasmids c. meiotic recombination d. crossing over e. mutation Use the following answers for the following questions. The answers may be used once, more than once, or not at all. A. transduction B. transposition C. translation D. transformation E. conjugation ____ 161. External DNA is assimilated by a cell. a. A b. B c. C d. D e. E ____ 162. DNA is transferred from one bacterium to another by a virus. a. A b. B c. C d. D e. E ____ 163. A group of F+ bacteria is mixed with a group of F bacteria. After several days, all of the bacteria are F+. a. A b. B c. C d. D e. E ____ 164. A plasmid is exchanged between bacteria through a pilus. a. A b. B c. C d. D e. E ____ 165. A sequence of DNA is moved to alternative locations within the genome. a. A b. B c. C d. D e. E ____ 166. In biotechnology, genes are commonly introduced into bacterial cells by incubating the cells together with DNA and high concentrations of calcium ions. This is an example of ____ 167. ____ 168. ____ 169. ____ 170. ____ 171. ____ 172. ____ 173. a. transformation. b. translocation. c. transduction. d. conjugation. e. transposition. The process by which host cell DNA is accidentally packaged within a phage capsid and transferred to another cell instead of the phage DNA is called a. translocation. b. conjugation. c. specialized transduction. d. generalized transduction. e. transformation. A scientist is studying a strain of bacteria that commonly transfers genes to other bacteria. Which of the following would provide evidence that the genes are being transferred through specialized transduction? a. Transmission of the genes is always accompanied by transfer of the F plasmid. b. Transmission of the genes is always accompanied by transfer of the R plasmid. c. The same one or several gene(s) are always transferred. d. The transmission of the genes is dramatically enhanced in the presence of calcium. e. The bacterial strain is often infected by a virulent phage. What does bacterial mating involve? a. exchange of egg and sperm b. formation of a cytoplasmic bridge for the transfer of "male" DNA c. sex pili that draw the cells together so that mRNA can be inserted d. integration of male and female DNA into a cytoplasmic bridge e. binary fission of a bacterial cell An Hfr bacterium is one that has a. at least one plasmid present in the cytosol. b. a special recognition site that will take up closely related DNA from its environment. c. several insertion sequences scattered throughout its chromosome. d. several copies of a single transposon repeated randomly throughout its chromosome. e. a plasmid that has become integrated into its chromosome. Which of the following statements regarding transposons is not true? a. Transposons are genes that encode sex pili and enable plasmid transfers between bacteria. b. Transposons are found in both prokaryotes and eukaryotes. c. Transposons can move from a plasmid to the bacterial circular chromosome. d. Transposons may replicate at an original site and insert a copy at another site. e. Transposons may carry only the genes necessary for insertion. An R plasmid can a. facilitate bacterial resistance to antibiotics. b. adjust the rates of metabolic pathways. c. repress gene expression. d. convert an F+ to an F bacterium. e. reverse the direction of transcription. What does the operon model attempt to explain? a. the coordinated control of gene expression in bacteria b. bacterial resistance to antibiotics c. how genes move between homologous regions of DNA d. the mechanism of viral attachment to a host cell e. horizontal transmission of plant viruses ____ 174. All of the following are made up of nucleic acid except a a. repressor. b. structural gene. c. promoter. d. regulatory gene. e. operator. ____ 175. The role of a metabolite that controls a repressible operon is to a. bind to the promoter region and decrease the affinity of RNA polymerase for the promoter. b. bind to the operator region and block the attachment of RNA polymerase to the promoter. c. increase the production of inactive repressor proteins. d. bind to the repressor protein and inactivate it. e. bind to the repressor protein and activate it. ____ 176. The tryptophan operon is a repressible operon that is a. permanently turned on. b. turned on only when tryptophan is present in the growth medium. c. turned off only when glucose is present in the growth medium. d. turned on only when glucose is present in the growth medium. e. turned off whenever tryptophan is added to the growth medium. For the following questions, match the terms below with the appropriate phrase or description below. Each term can be used once, more than once, or not at all. A. operon B. inducer C. promoter D. repressor E. corepressor ____ 177. This protein is produced by a regulatory gene. a. A b. B c. C d. D e. E ____ 178. A mutation in this section of DNA could influence the binding of RNA polymerase to the DNA. a. A b. B c. C d. D e. E ____ 179. A lack of this nonprotein molecule would result in the inability of the cell to "turn off" genes. a. A b. B c. C d. D e. E ____ 180. A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in a. continuous transcription of the structural gene controlled by that regulator. b. complete inhibition of transcription of the structural gene controlled by that regulator. c. irreversible binding of the repressor to the operator. ____ 181. ____ 182. ____ 183. ____ 184. ____ 185. ____ 186. ____ 187. d. inactivation of RNA polymerase. e. both B and C The lactose operon is likely to be transcribed when a. there is more glucose in the cell than lactose. b. the cyclic AMP levels are low. c. there is lactose but no glucose in the cell. d. the cyclic AMP and lactose levels are both high within the cell. e. both C and D Transcription of the structural genes in an inducible operon a. occurs all the time. b. starts when the pathway's substrate is present. c. starts when the pathway's product is present. d. stops when the pathway's product is present. e. does not produce enzymes. Which of the following statements about operons is (are) true? a. The tryptophan operon is a repressible operon. b. Tryptophan itself can bind to the trp operator and shut down production of tryptophan pathway enzymes. c. The lactose operon repressor binds to the operator and turns on the synthesis of the enzyme galactosidase. d. Only A and C are correct. e. A, B, and C are correct. How does active CAP induce expression of the genes of the lactose operon? a. It terminates production of repressor molecules. b. It degrades the substrate allolactose. c. It stimulates splicing of the encoded genes. d. It stimulates the binding of RNA polymerase to the promoter. e. It binds steroid hormones and controls translation. For a repressible operon to be transcribed, which of the following must be true? a. A corepressor must be present. b. RNA polymerase and the active repressor must be present. c. RNA polymerase must bind to the promoter, and the repressor must be inactive. d. RNA polymerase cannot be present, and the repressor must be inactive. e. RNA polymerase must not occupy the promoter, and the repressor must be inactive. Allolactose induces the synthesis of the enzyme lactase. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose) as a potential food source. Which of the following occurs when the lactose enters the cell? a. The repressor protein attaches to the regulator. b. Allolactose binds to the repressor protein. c. Allolactose binds to the regulator. d. The repressor protein and allolactose bind to RNA polymerase. e. RNA polymerase attaches to the regulator. Of the following, which is least related to the others? a. corepressor b. repressor c. inducer d. transposon e. cAMP receptor protein

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UC Riverside - BIO - 5
Biology, 7e (Campbell)Chapter 17: From Gene to ProteinChapter Questions6) We now know that the one gene-one enzyme hypothesis is not entirely accurate because A) many genes code for proteins that are not enzymes. B) a single gene codes for a singl
UC Riverside - BIO - 5
Raven/Johnson Biology 8eChapter 17 Answers1. A recombinant DNA molecules is one that is a. produced through the process of crossing over that occurs in meiosis b. constructed from DNA from different sources c. constructed from novel combinations
UC Riverside - BIO - 5
Chapter 17MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Beadle and Tatum proposed the one gene-one enzyme concept. In its original form, this hypothesis could now be restated in which of th
UC Riverside - BIO - 5
Biology, 8e (Campbell) Chapter 101Photosynth esis Multiple-Choice Questions2)Which of following are products of the light reactions of photosynthesis that are utilized in the Calvin the cycle? A)CO2 and B)glucoseH2O and O2 C)ADP, Pi,
UC Riverside - BIO - 5
Raven/Johnson Biology 8eChapter 16 Answers1. Control of gene expression can occur at which of the following steps? a. Splicing of pre-mRNA into mature mRNA b. Initiation of translation c. Initiation of transcription d. All of the above The correc
UC Riverside - BIO - 5
chapter 16Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. _ 1. For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic
UC Riverside - BIO - 5
Raven/Johnson Biology 8eChapter 15 Answers1. The experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that a. bread mold can be grown in a lab on minimal media b. X-rays can damage DNA c. cells need enzymes d.
UC Riverside - BIO - 5
Chapter 15 Test Questions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) There is good evidence for linkage when (A)two genes occur together in the same gamete. (B)a gene is associated with a
UC Riverside - BIO - 5
chapter 14Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. _ 1. Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except tha
UC Riverside - BIO - 5
Raven/Johnson Biology 8eChapter 131. Why is the white-eye phenotype always observed in males carrying the white-eye allele? a. Because the trait is dominant b. Because the trait is recessive c. Because the allele is located on the X chromosome an
UC Riverside - BIO - 5
Biology, 7e (Campbell)Chapter 12: The Cell CycleChapter Questions1) The centromere is a region in which A) chromatids are attached to one another. B) metaphase chromosomes become aligned. C) chromosomes are grouped during telophase. D) the nucleus
UC Riverside - BIO - 5
Raven/Johnson Biology 8e 1. A true-breeding plant is one that a. produces offspring that are different from the parent b. forms hybrid offspring through cross-pollination c. produces offspring that are always the same as the parent d. can only reprod
UC Riverside - CHEM - 01c
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UC Riverside - CHEM - 01c
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UC Riverside - CHEM - 01c
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UC Riverside - CHEM - 01c
CHEMISTRY 1C Teaching Assistant Office Hours Finals Week Spring 2009Monday, June 8 8:00 - 9 9:00 - 10 10:00 - 11 11:00 - 12 12:00 - 1 1:00 - 2 2:00 - 3 3:00 - 4 4:00 - 5 5:00 - 6 Tuesday, June 9Daryl Bulloch David Weinberger Chris Jones Eric Knuds
UC Riverside - CHEM - 01c
Midterm I - 150 points - 10/18/2007 Version A1. Which of the following acids has the lowest pH? 0.1 M HBO, pKa = 2.43 0.1 M HA, pKa = 4.55 0.1 M HMO, pKa = 8.23 0.1 M HST, pKa = 11.89 pure water A. HA B. HST C. HMO D. HBO E. pure water 2. Consider
UC Riverside - CHEM - 01c
Midterm II - 150 points - 11/13/2007 - Version A1. Which relationship or statement best describes S for the following reaction? K2SO4(s) 2K+(aq) + SO42-(aq) A. S 0 B. S < 0 C. S > 0 D. S = H/T E. More information is needed to make a reasonable pre
UC Riverside - CHEM - 01c
Midterm I Chem 1C Section 20 Version AStudent: _1. Arsenic acid, H3AsO4, is used industrially to manufacture insecticides. Arsenic acid is a polyprotic acid with K1 = 2.5 10-4, K2 = 5.6 10-8, and K3 = 3 10-13. What is the concentration of the H
UC Riverside - CHEM - 01c
Midterm III Chem 1C Section 20 Version D Key1. (p. 904) Consider the reaction CuO(s) + H2(g) Cu(s) + H2O(l) In this reaction, which substances are the oxidant and reductant, respectively?A.CuO and H2b. H2 and CuO c. CuO and Cu d. H2O and H2 e
UC Riverside - BIO - 05lc
Biology 05B Spring Quarter 2009Lab 1 page 1The ProtistsThe term protist refers to an organism belonging to an alliance of organisms that are diverse in form, life style, and ancestry. The primary feature that distinguishes protists from other
UC Riverside - BIO - 05lc
Biology 05B Spring Quarter 2009Lab 2 page 1Animal Diversity I Biological Classification, an Introduction to 2 Animal Phyla, and Animal Development.Contents: 1. 2. 3. 4. Topic Biological Classification Phylum Porifera the Sponges Phylum Cnida
UC Riverside - BIO - 05lc
Biology 05B Spring Quarter 2009Lab 3 page 1Animal Diversity II The Lower Invertebrates (Worms).Contents: Topic 1. 2. 3. 4. 5. 1. INTRODUCTION A. PERSPECTIVE Last week our study of animal diversity began with a look at two phyla that included
UC Riverside - BIO - 05lc
Biology 05B Spring Quarter 2009Lab 4 page 1Animal Diversity III The Higher InvertebratesContents: Topic 1. Introduction 2. Phylum Arthropoda 3. Phylum Mollusca 4. Phylum Echinodermata 1. INTRODUCTION The term "higher invertebrates" is not a t
UC Riverside - BIO - 05lc
Biology 05B Spring Quarter 2009Lab 5 page 1ENERGY METABOLISM Contents: TopicI. II. III. IV. IntroductionMetabolic Rate And Temperature in aMousePage 1 3 4 4Metabolic Rate And Temperature in anInsect CalculationsI. INTRODUCTION In pho
UC Davis - NPB - 101L
Important Notes Concerning Lab Exercise 4 Auscultation: 1. Auscultation taking blood pressure with a Sphygmomanometer a. Keep the room QUIET! b. Stethoscope ear pieces should be pointing forward c. Some stethoscopes have an ON/OFF switch. Place scop
UC Davis - BIS - 103
BIS103-001 (Spring 2005) Midterm #2 (May 19) Instructor: AbelName_ANSWER KEY Student ID #_Pls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 6 questions. A
UC Davis - BIS - 103
BIS103-001 (Spring 2006) Final Exam (June 9) Instructor: AbelName_ANSWER KEY Student ID #_Pls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 5 questions. A
UC Davis - BIS - 103
BIS103-001 (Spring 2006) Midterm #2 (May 18) Instructor: AbelName_ANSWER KEY_ Student ID #_Pls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 6 questions.
UC Davis - BIS - 103
BIS103-002 (Spring 2008) Final Exam (June 9) Instructor: AbelName_ Student ID # ANSWER KEYPls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 6 questions. A
UC Davis - BIS - 103
BIS103-001 (Spring 2004) Final Exam (June 11) Instructor: AbelName_ Student ID # ANSWER KEYUndergraduate Student Graduate Student Auditing Completing IncompletePlease, check appropriate box.This exam consists of 6 questions. A maximum of 100 p
UC Davis - BIS - 103
BIS103-001 (Spring 2004) Midterm #1 (April 22) Instructor: AbelName_ Student ID #_Undergraduate Student Graduate Student Auditing Completing IncompletePlease, check appropriate box.This exam consists of 6 questions. A maximum of 100 points can
UC Davis - BIS - 103
BIS103-001 (Spring 2004) Midterm #2 (May 20) Instructor: AbelName_ Student ID #_ ANSWER KEYUndergraduate Student Graduate Student Auditing Completing IncompletePlease, check appropriate box.This exam consists of 6 questions. A maximum of 100 p
UC Davis - BIS - 103
BIS103-001 (Spring 2004) Midterm #2 (May 20) Instructor: AbelName_ Student ID #_Undergraduate Student Graduate Student Auditing Completing IncompletePlease, check appropriate box.This exam consists of 6 questions. A maximum of 100 points can be
UC Davis - BIS - 103
BIS103-001 (Spring 2005) Midterm #1 (April 21) Instructor: AbelName_ANSWER KEY_ Student ID #_Pls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 7 questions
UC Davis - BIS - 103
BIS103-001 (Spring 2006) Midterm #1 (April 25) Instructor: AbelName_ Student ID # ANSWER KEYPls., check appropriate box below.Undergraduate Student Completing Incomplete Open Enrollment Student Graduate Student This exam consists of 7 questions.
UC Davis - BIS - 103
BIS103-001 (Spring 2004) Midterm #1 (April 22) Instructor: AbelName_ Student ID #_Undergraduate Student Graduate Student Auditing Completing IncompletePlease, check appropriate box.This exam consists of 6 questions. A maximum of 100 points can
UC Davis - NPB - 101L
Important Notes Concerning Lab Exercise 6 Static Lung Volume Measurements: 1. Select a subject who is not sick, have asthma or other respiratory disease 2. Place cardboard mouthpiece into the flow-meter before use 3. Lock your lips firmly around mout
UC Davis - NPB - 101L
Important Notes Concerning Lab Exercise 8 1. We use two different types of Ringer Tyrodes solution in this lab: normal and Ca+2-free. Make sure you are using the right one for each portion of the lab! 2. Monitor temperature carefully: should be betwe
UC Davis - NPB - 101L
Experiment 2: Skeletal Muscle 3 kinds of muscle: (1) skeletal (2) cardiac and (3) smooth Muscle fiber: Basic unit of contraction. It is multinucleated (10-100 uM) and contains myofibrils. Contractile unit of myofibril: actin and myosin filaments Musc
UC Davis - NPB - 101L
Experiment 3: Human Reflexes Reflex: A Patterned involuntary response to a stimulus which reduces or limits the effect of the stimulus. Monosynaptic (Hoffman reflex) Polysynaptic ( eg. Recurrent inhibition) Reflex Arc: Receptor Afferent nerve fiber
UC Davis - NPB - 101L
Lab 4: Human Cardiovascular System The heart acts as a pump in the vascular system that pumps blood through the systemic and pulmonary circulations. The blood vessels act as conduits through which blood is transported or thin-walled membranes through
UC Davis - NPB - 101L
Lab 5: Electrical and Mechanical Properties of the Heart Heart : primary pump of the cardiovascular system Creates a pressure gradient on the arterial side that allows blood flow to tissues In humans, dual pump systemic blood movement through the
UC Davis - NPB - 101L
Lab 6: Mechanics and Control of Lung Ventilation Respiratory system Functions: GAS EXCHANGE, vocalization, regulation of temperature and pH Internal Respiration: - gas utilization and production in mitochondria and cells External Respiration: gas exc
UC Davis - NPB - 101L
Lab 7: Renal Lab Functions of the Renal System: 1) regulation of extracellular fluid. Homeostatic control of (a) electrolytes (b) pH (c) H2O content and (d) total fluid volume Renal system : Kidneys, bladder, urinary tracts and renal blood supply Kid
UC Davis - NPB - 101L
Intestinal Motility GI Tract: Primary Function: ingestion, digestion and assimilation of food followed by a removal of wastes. Ingestion : taking in food into the GI tract. Secretion: a) Exocrine: move into the lumen of the GI tract and function eg.
UC Davis - NPB - 101L
Quiz 2 Study Sheet Reflex: A response that occurs automatically, without any brain involvement, to protect the body. Stimulus to response mediated by a neural pathway known as the reflex arc Reflex arc: Neural pathway that does not include the brain
UC Davis - NPB - 101L
Quiz 3 Study Sheet Basic organization of the cardiovascular systemCardiovascular System Consists of: 1) Heart: Two pumps a) Right side: pumps blood to lungs b) Left side: pumps blood to rest of body Four chambers: 2 atria and 2 ventricles 2) Blood
UC Davis - NPB - 101L
Concepts to Know for Quiz 5 Anatomy of the respiratory system:Trachea: Moves air and branches to bronchi Bronchi: Branch to bronchioles Brochioloes: Composed entirely of smooth muscles and terminate at the alveoli Alveoli: Small sacs surrounded by
UC Davis - NPB - 101L
Quiz 7 Study Sheet 4 Basic Digestive Processes (I know the lab manual says three): 1. Motility: Muscular contractions that mix and move contents forward in digestive tract a. tone: Smooth muscles in walls of digestive tract maintain a low level of co
UC Davis - NPB - 101L
NPB101L Section 2 TA: Jen LeeLab 8: Intestinal Motility Gastrointestinal smooth muscle: 2 major layers of smooth muscle -Outer longitudinal Inner circularCharacteristics and mechanisms Not striated, misalignment of actin and myosin; unitary t
UC Davis - NPB - 101L
LAB 6 STUDY SHEETSubjectSpecific GravityUrine pHUrine Flow RateGFRCreatinine ClearanceNa+ Clearance(Describes changes in above parameters over time) LTC = Lower than control, HTC = Higher than control SAC = Same as control Control
UC Davis - NPB - 101L
Intestinal Motility GI Tract: Primary Function: ingestion, digestion and assimilation of food followed by a removal of wastes. Ingestion : taking in food into the GI tract. Secretion: a) Exocrine: move into the lumen of the GI tract and function eg.
UC Davis - NPB - 101L
Major functions of the kidney: 1. Excretory rids the body of nitrogenous waste and acid 2. Homeostasis maintains normal body concentrations of Na+, K+, Cl-, HCO3-, Ca2+, Mg2+, PO4-, and water 3. Endocrine secretes multiple hormones. Renin (enzyme
UC Davis - PMI - 126
UC Davis - PMI - 126
UC Davis - PMI - 126
VM PMI 1261.1ST MIDTERM EXAMINATIONWINTER 2007Which of the following infectious diseases have been successfully managed by vaccination programs? a. AIDS (acquired immunodeficiency syndrome) b. High cholesterol c. Breast cancer d. Small pox e.
National College of Natural Medicine - ISE - ISE 103
This is the html version of the file http:/www.personal.kent.edu/~sschindl/nm/files/reviewQ.doc. Google automatically generates html versions of documents as we crawl the web.Chapter 1 SolutionsReview Questions1. What was the only method of shari
UCSD - ECE - 174
St. Edwards - BUSI - 4312
Justin Gardiner Dr. Ward BUSI 4349 8 March 2009 Regal Entertainment Group: The Movie Theater Segment of the Entertainment IndustryCurrent Strategy: REG currently attributes 67 percent of revenue from ticket sales, 26 percent from concessions, and t
St. Edwards - BUSI - 4312
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