Life 9e - garvness.webs.com Test File-Fro… · Web viewChapter 14: From DNA to Protein: Gene Expression. TEST FILE QUESTIONS (By Catherine Ueckert) Multiple Choice. 1. Tuberculosis

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Life: The Science of Biology, Ninth EditionSadava • Hillis • Heller • Berenbaum

Chapter 14: From DNA to Protein: Gene Expression

TEST FILE QUESTIONS(By Catherine Ueckert)

Multiple Choice

1. Tuberculosis is a world health issue, killing over a million people annually. Several antibiotics have been developed to treat Mycobacterium tuberculosis, the bacterium that causes the disease. Essentially the antibioticsa. kill the bacteria directly.b. inhibit bacterial protein synthesis.c. alleviate the bloody cough, fever, and chills so the patient can recover comfortably.d. produce a lethal toxin that destroys the bacteria.e. breaks peptide bonds preventing gene expression.Answer: bTextbook Reference: 14.0 An unexpected wedding giftPage: 290–291Bloom’s Category: 3. Applying

2. Genetic material is composed ofa. DNA.b. amino acids.c. ribose.d. carbohydrates.e. lipids.Answer: aTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 291Bloom’s Category: 1. Remembering

3. The major phenotypic expression of genotype is ina. proteins.b. tRNA.c. mRNA.d. nucleic acids.e. rRNA.Answer: aTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?

Page: 291Bloom’s Category: 1. Remembering

4. Which of the following are model organisms used in biological research?a. Pea plantsb. Fruit fliesc. E. colid. Bread molde. All of the aboveAnswer: eTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292Bloom’s Category: 1. Remembering

5. After irradiating Neurospora, Beadle and Tatum collected mutants that woulda. not grow on a minimal medium but would grow on a minimal medium with arginine.b. grow on any minimal medium.c. not grow on any minimal medium.d. grow on a minimal medium but would not grow on a minimal medium with arginine.e. None of the aboveAnswer: aTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 293Bloom’s Category: 1. Remembering

6. Within a group of mutants with the same growth requirement (i.e., the same overt phenotype), mapping studies determined that individual mutations were on different chromosomes. This indicates thata. the same gene governs all the steps in a particular biological pathway.b. different genes can govern different individual steps in the same biological pathway.c. different genes govern the same step in a particular biological pathway.d. all biological pathways are governed by different genes.e. genes do not govern steps in biological pathways.Answer: bTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 293Bloom’s Category: 4. Analyzing

7. The study of Neurospora mutants grown on various supplemented media led toa. a determination of the steps in biological pathways.b. the one-gene, one-enzyme hypothesis.c. the idea that genes are “on” chromosomes.d. Both a and be. Both a and cAnswer: dTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?

Page: 293Bloom’s Category: 2. Understanding

8. The classic work of Beadle and Tatum, later refined by others, provided evidence for thea. one-gene, one-enzyme hypothesis.b. one-gene, one-polypeptide hypothesis.c. mechanism by which information in genes is translated into traits.d. effects of some mutations on organisms.e. All of the aboveAnswer: eTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 293–294Bloom’s Category: 2. Understanding

9. Genes code fora. enzymes.b. polypeptides.c. RNA.d. All of the abovee. None of the aboveAnswer: dTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 294Bloom’s Category: 1. Remembering

10. How does RNA differ from DNA?a. RNA contains uracil instead of thymine and it is usually single-stranded.b. RNA contains uracil instead of thymine and it is usually double-stranded.c. RNA contains thymine instead of uracil and it is usually single-stranded.d. RNA contains uracil instead of cytosine.e. None of the aboveAnswer: aTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294Bloom’s Category: 2. Understanding

11. Which of the following molecules transfers information from the nucleus to the cytoplasm?a. DNAb. mRNAc. tRNAd. Proteinse. LipidsAnswer: bTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?


12. The link between mRNA and a protein isa. tRNA.b. a promoter.c. RNA polymerase.d. DNA polymerase.e. a start codon.Answer: aTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294Bloom’s Category: 2. Understanding

13. Which of the following molecules transfers information from mRNA to protein?a. DNAb. mRNAc. tRNAd. Proteinse. LipidsAnswer: cTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294Bloom’s Category: 1. Remembering

14 The “central dogma” of molecular biology states thata. information flow between DNA, RNA, and protein is reversible.b. information flow in the cell is unidirectional, from protein to RNA to DNA.c. information flow in the cell is unidirectional, from DNA to RNA to protein.d. the DNA sequence of a gene can be predicted if we know the amino acid sequence of the protein it encodes.e. the genetic code is ambiguous but not degenerate.Answer: cTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294Bloom’s Category: 2. Understanding

15. The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are calleda. aminoacyl tRNA synthetases.b. transfer RNAs.c. ribosomal RNAs.d. messenger RNAs.e. ribosomes.Answer: bTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?


16. Which of the following statements about the flow of genetic information is true?a. Proteins encode information that is used to produce other proteins of the same amino acid sequence.b. RNA encodes information that is translated into DNA, and DNA encodes information that is translated into proteins.c. Proteins encode information that can be translated into RNA, and RNA encodes information that can be transcribed into DNA.d. DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins.e. None of the aboveAnswer: dTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294–295Bloom’s Category: 2. Understanding

17. Gene expression can be regulateda. before transcription.b. during transcription and before translation.c. during translation.d. after translation.e. All of the aboveAnswer: eTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294–295Bloom’s Category: 2. Understanding

18. Single-stranded RNA replicates bya. making an RNA strand that is complementary to the original RNA strand.b. using an adapter molecule.c. the process of transcription.d. the process of translation.e. the process of reverse transcription.Answer: aTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 295Bloom’s Category: 2. Understanding

19. Which of the following does (do) not follow the “central dogma”?a. Yeastb. Onion cellsc. Bread moldd. Skin cellse. Retroviruses

Answer: eTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 295–296Bloom’s Category: 2. Understanding

20. Retroviruses do not follow the “central dogma” of DNA → RNA → protein because theya. contain RNA that is used to make DNA.b. contain DNA that is used to make more RNA.c. contain DNA that is used to make tRNA.d. contain only DNA as the genetic material.e. do not contain either DNA or RNA as the genetic material.Answer: aTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 295–296Bloom’s Category: 2. Understanding

21. Viruses that violate the “central dogma” through the use of an enzyme that makes DNA copies of an RNA molecule are calleda. bacteriophage.b. retroviruses.c. RNA viruses.d. DNA viruses.e. enveloped viruses.Answer: bTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 296Bloom’s Category: 1. Remembering

22. Transcription is the process ofa. synthesizing a DNA molecule from an RNA template.b. assembling ribonucleoside triphosphates into an RNA molecule without a template.c. synthesizing an RNA molecule using a DNA template.d. synthesizing a protein using information from a messenger RNA.e. replicating a single-stranded DNA molecule.Answer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

23. The process of transcription synthesizesa. transfer RNA.b. messenger RNA.c. ribosomal RNA.d. proteins.

e. a, b, and cAnswer: eTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 2. Understanding

24. The region of DNA in prokaryotes to which RNA polymerase binds most tightly is thea. promoter.b. poly C center.c. enhancer.d. operator site.e. minor groove.Answer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 2. Understanding

25. Promoters are made ofa. proteins.b. carbohydrates.c. lipids.d. nucleic acids.e. amino acids.Answer: dTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

26. A transcription start signal is called a(n)a. initiation codon.b. promoter.c. origin.d. operator.e. nonsense codon.Answer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

27. RNA polymerase isa. an RNA-directed DNA polymerase.

b. an RNA-directed RNA polymerase.c. a DNA-directed RNA polymerase.d. a typical enzyme.e. a form of RNA.Answer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 2. Understanding

28. DNA is composed of two strands, only one of which typically is used as a template for RNA synthesis. By what mechanism is the correct strand chosen?a. Both strands are tried, and the one that works is remembered.b. Only one strand has the start codon.c. The promoter acts to aim the RNA polymerase.d. A start factor informs the system.e. It is chosen randomly.Answer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 2. Understanding

29. In bacteria, there is/are _______ RNA polymerase(s) that catalyze the synthesis of RNA from DNA.a. oneb. threec. fourd. fivee. sixAnswer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

30. RNA polymerase uses the _______ DNA template to synthesize a _______ mRNA.a. 5´ to 3´; 5´ to 3´b. 3´ to 5´; 3´ to 5ć. 5´ to 3´; 3´ to 5´d. 3´ to 5´; 5´ to 3é. Examples of all of the above have been found.Answer: dTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 297

Bloom’s Category: 2. Understanding

31. The direction of synthesis for a new mRNA molecule is _______ from a _______ template strand.a. 5´ to 3´; 5´ to 3´b. 5´ to 3´; 3´ to 5ć. 3´ to 5´; 5´ to 3´d. 3´ to 5´; 3´ to 5é. 5´ to 5´; 3´ to 3Ánswer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 297Bloom’s Category: 4. Analyzing

32. Errors in transcription are not as potentially harmful as errors in DNA replication becausea. many copies of RNA are made.b. RNA strands have a relatively short life span.c. RNA polymerases proofread and correct the errors.d. a and b are correcte. a, b, and c are correctAnswer: dTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 2. Understanding

33. The process of transcription requiresa. a temporary stopping of DNA replication.b. a temporary separation of the strands in the DNA template.c. destruction of one of the strands of the DNA template.d. relaxation of positive supercoils in the DNA template.e. induction of positive supercoils in the DNA template.Answer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 2. Understanding

34. There are differences in the amount of transcription that takes place for different genes. One reason for these differences is thata. some promoters are more effective at transcription initiation.b. longer genes take longer to transcribe.c. the outcome is influenced by random chance.d. ribosomes tend to attach to transcripts even before transcription is completed.

e. None of the aboveAnswer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 2. Understanding

35. Termination of transcription involves aa. stop codon.b. terminator sequence.c. termiproteator.d. hairline slip.e. series of As.Answer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 1. Remembering

36. There are _______ different RNA polymerases in eukaryotes.a. twob. threec. fourd. fivee. sixAnswer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 1. Remembering

37. The termination of transcription is signaled bya. the stop codon.b. a sequence of nitrogenous bases.c. a protein bound to a certain region of DNA.d. rRNA.e. tRNA.Answer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 2. Understanding

38. Imagine that a novel life-form is found deep within Earth’s crust. Evaluation of its DNA yields no surprises. However, it is found that a codon for this life-form is just two bases in length. How many different amino acids could this organism be composed of?

a. 4b. 8c. 16d. 32e. 64Answer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298Bloom’s Category: 3. Applying

39. How can DNA, which is made up of only four different bases, encode the information necessary to specify the workings of an entire organism?a. DNA molecules are extremely long.b. DNA molecules form codons of three bases that code for amino acids.c. The genetic code is redundant but not ambiguous.d. DNA can be replicated with low error rates.e. All of the aboveAnswer: eTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298–299Bloom’s Category: 4. Analyzing

40. The stop codons code fora. no amino acid.b. methionine.c. glycine.d. halt enzyme.e. DNA binding protein.Answer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 2. Understanding

41. How many codons specify amino acids?a. 20b. 23c. 45d. 60e. 61Answer: eTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299

Bloom’s Category: 1. Remembering

42. The genetic code is best described asa. redundant but not ambiguous.b. ambiguous but not redundant.c. both ambiguous and redundant.d. neither ambiguous nor redundant.e. nonsense.Answer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 1. Remembering

43. The three codons in the genetic code that do not specify amino acids are calleda. missense codons.b. start codons.c. stop codons.d. promoters.e. initiator codons.Answer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 1. Remembering

44. A template DNA strand has the following base sequence: 3´-GUC, CCA-5´. What would be the corresponding mRNA sequence?a. 3´-GUC, CCA-5´b. 5´-GUC, CCA-5ć. 3´-CAG, GGU-5´d. 5´-CAG, GGU-3é. 5´-CAG, GGT-3Ánswer: dTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 3. Applying

45. Poly uracil codes fora. three different amino acids.b. poly tryptophan.c. mRNA.d. a fatty acid.e. phenylalanine.Answer: e

Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 1. Remembering

46. Exons area. translated.b. found in most prokaryotic genes.c. removed during RNA processing.d. Both a and be. Both a and cAnswer: aTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 300Bloom’s Category: 2. Understanding

47. Exons area. spliced out of the original transcript.b. spliced together from the original transcript.c. spliced to introns to form the final transcript.d. much larger than introns.e. larger than the original coding region.Answer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 300Bloom’s Category: 2. Understanding

48. The regions of DNA in a eukaryotic gene that contain noncoding base sequences are calleda. enhancers.b. mRNAs.c. hnRNAs.d. introns.e. leader sequences.Answer: dTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 300Bloom’s Category: 1. Remembering

49. Nucleic acid hybridizationa. is used to study the relationship between eukaryotic genes and their transcripts.b. requires that the original DNA molecule be denatured.c. involves the use of a probe to form a double-stranded molecule.d. originally revealed the existence of introns.e. All of the aboveAnswer: e

Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 301Bloom’s Category: 1. Remembering

50. When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops of double-stranded DNA, which area. retroviruses.b. introns.c. exons.d. transcripts.e. puffs.Answer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 301Bloom’s Category: 2. Understanding

51. The tail added to pre-mRNA isa. coded for by DNA.b. composed of poly T.c. important for mRNA stability.d. attached to its 5´ end.e. All of the aboveAnswer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302Bloom’s Category: 2. Understanding

52. The guanosine triphosphate (GTP) cap that is added to the 5´ end of primary mRNAa. contains all the coding and noncoding sequences of the DNA template.b. provides the mRNA molecule with a poly A tail.c. facilitates the binding of mRNA to ribosomes.d. forms hydrogen bonds.e. helps transfer amino acids to the ribosomes.Answer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302Bloom’s Category: 2. Understanding

53. The modified G cap on eukaryotic mRNAs is founda. at the 5´ end.b. at the 3´ end.c. in the consensus sequence.d. in the poly A tail.e. in snRNA.Answer: aTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?


54. Poly A tailsa. are added after transcription.b. are encoded by a sequence of thymines in the DNA.c. are found in all mRNAs.d. have no function.e. are removed during RNA processing.Answer: aTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302Bloom’s Category: 1. Remembering

55. Chromosomes of eukaryotic DNA must havea. DNA sequences that make up telomeres and centromeres.b. proteins that are centromeres and DNA that form telomeres.c. a 5´ G cap.d. an inactivation center.e. None of the aboveAnswer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302Bloom’s Category: 2. Understanding

56. Which of the following is not part of RNA processing in eukaryotes?a. Splicing of exonsb. Reverse transcriptionc. Addition of a 5´ capd. Addition of a poly A taile. Intron removalAnswer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302–303Bloom’s Category: 2. Understanding

57. What are the three processes that must be completed before transcripts can be translated in eukaryotes?a. Binding of snRNPs, addition of a poly A tail, splicing of intronsb. Binding of snRNPs, transporting, synthesizing of ribosec. Capping, transporting, synthesizing of ribosed. Binding of snRNPs, capping, splicinge. Splicing, capping, addition of a poly A tailAnswer: eTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302–303


58. RNA processing in eukaryotes involves thea. addition of a G cap.b. addition of a poly A tail.c. removal of introns.d. splicing of exons.e. All of the aboveAnswer: eTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 302–303Bloom’s Category: 2. Understanding

59. snRNPs area. exon–intron boundary regions.b. small nuclear ribonucleoprotein particles.c. protein fragments removed from snRNA molecules.d. signal ribosomal nuclear proteins.e. glucose-conjugated trapezoids.Answer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 303Bloom’s Category: 1. Remembering

60. The binding of snRNPs to consensus sequences is necessary fora. gene duplication.b. the addition of a poly A tail.c. capping an hnRNA.d. RNA splicing.e. transcription.Answer: dTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 303Bloom’s Category: 2. Understanding

61. Consensus sequences (short segments of DNA) appear in the boundaries between introns and exons of various genes. These sequences appear to be involved ina. directing the polymerases to the appropriate place on the DNA for transcription to begin.b. the splicing of introns out of the DNA.c. allowing the transcription to stop at the appropriate spot.d. catalyzing the synthesis of a protein.e. None of the aboveAnswer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 303


62. The conformation of tRNA is maintained bya. peptide bonds.b. hydrogen bonds.c. disulfide bridges.d. phosphodiester bonds.e. glycosidic linkages.Answer: bTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 303Bloom’s Category: 2. Understanding

63. Activating enzymesa. are sometimes referred to as the second genetic code.b. link the right tRNAs and amino acids.c. are also known as aminoacyl-tRNA synthetases.d. are specific for one amino acid.e. All of the aboveAnswer: eTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 303Bloom’s Category: 2. Understanding

64. What events must take place to ensure that the protein made is the one specified by mRNA?a. tRNA must read mRNA correctly.b. tRNA must carry the amino acid that is correct for its reading of the mRNA.c. Covalent bonding between the base pairs must occur.d. Both a and be. All of the aboveAnswer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

65. A sequence of three RNA bases can function asa. a codon.b. an anticodon.c. a gene.d. Both a and be. Both a and cAnswer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

66. The difference between mRNA and tRNA is thata. tRNA has a more elaborate three-dimensional structure.b. tRNAs are usually much smaller than mRNAs.c. mRNA carries amino acids.d. Both a and be. None of the aboveAnswer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

67. How is it possible for single-stranded RNA to fold into complex shapes?a. Phosphodiester linkages form between the phosphate and the sugar ribose.b. Internal base pairings make this possible: adenine with uracil and cytosine with guanine.c. Uracil’s methyl group binds to adenine, spiraling the molecule.d. The single strand “twists” around itself.e. The RNA binds to proteins, creating a conformation (three-dimensional shape).Answer: bTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

68. Fewer different tRNA molecules exist than might have been expected for the complexity of its function. This is possible becausea. the third position of the codon does not have to pair conventionally.b. the second position of the codon does not have to pair conventionally.c. the anticodon does not have the conventional bases.d. there are fewer amino acids than there are possible codons.e. the code is degenerating.Answer: aTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305Bloom’s Category: 2. Understanding

69. Which of the following statements about codons and anticodons is true?a. The codon bonds covalently with the anticodon.b. The base sequences are the same.c. There are 64 codons and 61 anticodons.d. Activating enzymes link codons and anticodons.e. At contact, the codon and the anticodon are antiparallel to each other.Answer: eTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305Bloom’s Category: 2. Understanding

70. The enzyme that charges the tRNA molecules with appropriate amino acids isa. tRNA chargeatase.b. amino tRNA chargeatase.c. transcriptase.d. aminoacyl-tRNA synthetase.e. None of the aboveAnswer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305Bloom’s Category: 1. Remembering

71. Ribosomes are a collection of _______ that are needed for _______.a. small proteins; translationb. proteins and small RNAs; translationc. proteins and tRNAs; transcriptiond. proteins and mRNAs; translatione. mRNAs and tRNAs; translationAnswer: bTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 306Bloom’s Category: 2. Understanding

72. During translation initiation, the first site occupied by a charged tRNA is thea. A site.b. B site.c. large subunit.d. T site.e. P site.Answer: aTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 306Bloom’s Category: 1. Remembering

73. The formation of a peptide bond between an amino acid at the P site and an amino acid at the A site during translation is catalyzed bya. the large ribosomal subunit.b. a specialized segment of DNA.c. a specialized segment of RNA.d. the initiation complex.e. initiation factors.Answer: aTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307Bloom’s Category: 2. Understanding

74. During translation elongation, the existing polypeptide chain is transferred toa. the tRNA occupying the A site.b. the tRNA occupying the P site.c. the ribosomal rRNA.d. a signal recognition particle.e. None of the aboveAnswer: bTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307Bloom’s Category: 2. Understanding

75. mRNA is synthesized in the _______ direction, which corresponds to the _______ of the protein.a. 5´ to 3´; N terminus to C terminusb. 3´ to 5´; C terminus to N terminusc. 5´ to 3´; C terminus to N terminusd. 3´ to 5´; N terminus to C terminuse. Examples of all of the above have been found.Answer: aTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307Bloom’s Category: 4. Analyzing

76. Proteins are synthesized from the _______, in the _______ direction along the mRNA.a. N terminus to C terminus; 5´ to 3´b. C terminus to N terminus; 5´ to 3ć. C terminus to N terminus; 3´ to 5´d. N terminus to C terminus; 3´ to 5é. N terminus to N terminus; 5´ to 5Ánswer: aTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 308Bloom’s Category: 2. Understanding

77. In protein synthesis, the endoplasmic reticuluma. is the site where mRNA attaches.b. is the site where all ribosomes bind.c. is the site of translation of membrane-bound and exported proteins.d. produces tRNAs.e. brings together mRNA and tRNA.Answer: cTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311Bloom’s Category: 2. Understanding

78. Which of the following is the correct order of events by which a protein is delivered to its cellular destination?a. A signal sequence binds to a docking protein, a membrane channel is formed, chaperonins unfold the protein, the protein enters the organelle, and the protein refolds.b. A membrane channel is formed, a signal sequence binds to a docking protein, chaperonins unfold the protein, the protein enters the organelle, and the protein refolds.c. Chaperonins unfold the protein, a signal sequence binds to a docking protein, a membrane channel is formed, the protein enters the organelle, and the protein refolds.d. A membrane channel is formed, chaperonins unfold the protein, a signal sequence binds to a docking protein, the protein enters the organelle, and the protein refolds.e. A signal sequence binds to a docking protein, a transmembrane-gated channel opens, and the protein enters the organelle.Answer: aTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311Bloom’s Category: 4. Analyzing

79. In eukaryotes, ribosomes become associated with endoplasmic reticulum membranes whena. a signal sequence on the mRNA interacts with a receptor protein on the membrane.b. a signal sequence on the ribosome interacts with a receptor protein on the membrane.c. a signal sequence at the amino terminus of the protein being synthesized interacts with a receptor protein on the ribosome.d. a signal sequence on the protein being synthesized interacts with a signal recognition particle and both bind to the endoplasmic reticulum.e. the messenger RNA passes through a pore in the membrane.Answer: dTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311Bloom’s Category: 2. Understanding

80. The addition of sugar residues to the protein after translation is calleda. glycation.b. glycosylation.c. phosphorylation.d. proteolysis.e. exonuclease digestion.Answer: bTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312Bloom’s Category: 1. Remembering

81. After translation, some proteins are processed by _______, which is cleavage of the protein to make a shortened finished protein.a. glycationb. glycosylation

c. phosphorylationd. proteolysise. exonuclease digestionAnswer: dTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312Bloom’s Category: 2. Understanding

82. In eukaryotic cells, proteins that contain covalently attached sugar residues are translateda. in the nucleus.b. in the cytoplasm.c. in mitochondria.d. on the endoplasmic reticulum.e. on the Golgi apparatus.Answer: dTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312Bloom’s Category: 2. Understanding

Fill in the Blank

1. Sometimes an antibiotic that has worked before no longer works because mutations in the bacterial genes have altered the amino acid sequence in the proteins so their three-dimensional structures will no longer bind to the antibiotic. This phenomenon is known as _______.Answer: antibiotic resistanceTextbook Reference: 14.0 An unexpected wedding giftPage: 290Bloom’s Category: 2. Understanding

2. Biologists often look for organisms that are easy to grow in the laboratory and that demonstrate the phenomenon they wish to study. These organisms are called _______ organisms.Answer: modelTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292Bloom’s Category: 1. Remembering

3. Certain agents, such as X rays, that are known to cause mutations are referred to as _______.Answer: mutagensTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292Bloom’s Category: 1. Remembering

4. Prototrophs (“original eaters”) grow on minimal media, whereas _______ (“increased eaters”) require specific additional nutrients.Answer: auxotrophsTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292Bloom’s Category: 2. Understanding

5. The one-gene, one-enzyme hypothesis resulted from the work of _______.Answer: Beadle and TatumTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 293Bloom’s Category: 1. Remembering

6. RNA differs from DNA in base composition in that it contains _______ instead of thymine.Answer: uracilTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294Bloom’s Category: 2. Understanding

7. The basic units of both DNA and RNA molecules are the _______.Answer: nucleotidesTextbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294–295Bloom’s Category: 1. Remembering

8. The strand of DNA that is transcribed into RNA is the _______ strand.Answer: templateTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

9. The synthesis of DNA from RNA is called _______.Answer: reverse transcriptionTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

10. The excess of codons (64) over amino acids (20) indicates that the genetic code is _______.Answer: redundantTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299


11. A noncoding base sequence found in eukaryotic cells is called a(n) _______.Answer: intronTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 300Bloom’s Category: 1. Remembering

12. The portion of the tRNA molecule that complementary base-pairs with the mRNA is called the _______.Answer: anticodonTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 1. Remembering

13. The fact that some tRNA molecules do not have to pair exactly is called _______.Answer: wobbleTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305Bloom’s Category: 1. Remembering

14. A tRNA that has bonded to an amino acid is referred to as _______ tRNA.Answer: chargedTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305Bloom’s Category: 1. Remembering

15. Small ribosomal subunits will disperse into smaller components when placed in a detergent solution. Upon removal of the detergent, the components will interact to create new intact subunits by a process called _______.Answer: self-assemblyTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 306Bloom’s Category: 2. Understanding

16. An mRNA molecule with several ribosomes attached is called a(n) _______.Answer: polysomeTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 308Bloom’s Category: 1. Remembering

17. The part of a protein that determines whether translation will continue in the cytosol or at the endoplasmic reticulum is the _______ sequence.Answer: signalTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 310


18. The addition of phosphate groups to polypeptide chains following translation is called _______.Answer: phosphorylationTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312Bloom’s Category: 1. Remembering

Diagram

1. Refer to the diagram below showing the process of gene expression in prokaryotes. The molecule responsible for carrying and delivering amino acids in the proper sequence is/are

a. rRNA.b. mRNA.c. tRNA.d. DNA.e. DNA and mRNA.Answer: cTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

STUDY GUIDE QUESTIONS

(By Nancy Guild)

Knowledge and Synthesis

1. Transcription in prokaryotic cellsa. occurs in the nucleus, whereas translation occurs in the cytoplasm.b. is initiated at a start codon with the help of initiation factors and the small subunit of the ribosome.c. is initiated at a promoter and uses only one strand of DNA (the template strand) to synthesize a complementary RNA strand.d. is terminated at stop codons.e. is initiated at an ori site on the chromosome.Answer: cFeedback: Answer a describes transcription and translation in eukaryotic cells; answers b and d describe translation. Answer e refers to the ori site, where replication of the circular chromosome starts.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296–298

2. Which of the following statements about RNA polymerase is false?a. It synthesizes mRNA in a 5´-to-3´ direction, reading the DNA strand 3´ to 5´.b. It synthesizes mRNA in a 3´-to-5´ direction, reading the DNA strand 5´ to 3´.c. It binds at the promoter and unwinds the DNA.d. It does not require a primer to initiate transcription.e. It uses only one strand of DNA as a template for synthesizing RNA.Answer: bFeedback: RNA polymerase binds at a promoter, unwinds the DNA, synthesizes mRNA in a 5´-to-3´ (not 3´-to-5´) direction, and does not require a primer to synthesize the RNA.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296–298

3. Translation of messenger RNA into protein occurs in a _______ direction, and from _______ terminus to _______ terminus.a. 3´-to-5´; N; Cb. 5´-to-3´; N; Cc. 3´-to-5´;C; Nd. 5´-to-3´; C; Ne. 3´-to-5´; C; CAnswer: bFeedback: Translation of messenger RNA occurs 5´ to 3´, and the polypeptide is synthesized from the N terminus to the C terminus.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307

4. If codons were read two bases at a time instead of three bases at a time, how many different possible amino acids could be specified?a. 16b. 64c. 8d. 32e. 128Answer: aFeedback: Four possible bases read two at a time would yield 42, or 16, different codons.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 298–299

5. Translate the following mRNA:3´ – G A U G G U U U U A A A G U A – 5á. NH2 met—lys—phe—leu—stop COOHb. NH2 met—lys—phe—trp—stop COOHc. NH2 asp—gly—phe—lys—val COOHd. NH2 met—gly—phe—lys—val COOHe. NH2 asp—gly—phe—lys—stop COOHAnswer: bFeedback: See the codon table (Figure 14.6). Recall that translation occurs in the 5´-to-3´ direction.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299

6. What would happen if a mutation occurred in DNA such that the second codon of the resulting mRNA was changed from UGG to UAG?a. Translation would continue and the second amino acid would be the same.b. Nothing. The ribosome would skip that codon and translation would continue.c. Translation would continue, but the reading frame of the ribosome would be shifted.d. Translation would stop at the second codon, and no functional protein would be made.e. Translation would continue, but the second amino acid in the protein would be different.Answer: dFeedback: UAG is a stop codon, so translation would terminate at that site.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299

7. If the following synthetic RNA were added to a test tube containing all the components necessary for protein translation to occur, what would the amino acid sequence be?5´ – A U A U A U A U A U A U – 3á. Polyphenylalanineb. Isoleucine–tyrosine–isoleucine–tyrosine

c. Isoleucine–isoleucine–isoleucine–isoleucined. Tyrosine–tyrosine–tyrosine–tyrosinee. Aspargine–aspargine–aspargine–aspargineAnswer: bFeedback: See the codon table (Figure 14.6).Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299

8. Which part of the tRNA base-pairs with the codon in the mRNA?a. The 3´ end, where the amino acid is covalently attachedb. The 5´ endc. The anticodond. The start codone. The promoterAnswer: cFeedback: Neither the 3´ end nor the 5´ end of the tRNA is part of the anticodon. The promoter is a DNA sequence, to which RNA polymerase binds to initiate transcription. The start codon is found in the mRNA.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304–305

9. Peptidyl transferase is ana. enzyme found in the nucleus of the cell that assists in the transfer of mRNA to the cytoplasm.b. enzyme that adds the amino acid to the 3´ end of the tRNA.c. enzyme found in the large subunit of the ribosome that catalyzes the formation of the peptide bond in the growing polypeptide.d. RNA molecule that is catalytic.e. Both c and dAnswer: eFeedback: Peptidyl transferase is the enzyme that catalyzes the formation of the peptide bond, and it is located in the large subunit of the ribosome. Its catalytic activity is due to ribosomal RNA found in the large subunit of the ribosome.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307

10. Termination of translation requiresa. a termination signal, RNA polymerase, and a release factor.b. a release factor, initiator tRNA, and ribosomes.c. initiation factors, the small subunit of the ribosome, and mRNA.d. elongation factors and charged tRNAs.e. a stop codon positioned at the A site of the ribosome, peptidyl transferase, and a release factor.Answer: e

Feedback: Termination of translation requires a stop codon positioned at the A site of the ribosome, peptidyl transferase, and a release factor. Peptidyl transferase hydrolyzes the last amino acid attached to the tRNA in the P site, creating the C terminus.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 308

11. If the DNA encoding a nuclear signal sequence were placed in the gene for a cytoplasmic protein, the protein woulda. be modified in the Golgi.b. be directed to the lysosomes.c. be directed to the nucleus.d. be directed to the cytoplasm.e. stay in the endoplasmic reticulum.Answer: cFeedback: The nuclear sequence would direct this protein to the nucleus.Textbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311

12. Auxotrophs are mutant strains thata. can grow on a minimal medium.b. require the addition of an essential nutrient to grow on a minimal medium.c. cannot make any enzymes.d. behave like wild-type strains.e. can grow only if arginine is added to the growth medium.Answer: bFeedback: Auxotrophs cannot grow on minimal medium and are not wild type. They are deficient in one enzyme in a particular biochemical pathway, but can make many other enzymes. Answer e is true only for arginine auxotrophs.Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292–293

13. The central dogma of molecular biology states that _______ is transcribed into _______, which is (are) translated into _______.a. a gene; polypeptides; a gene productb. protein; DNA; RNAc. DNA; mRNA; tRNAd. DNA; RNA; proteine. RNA; DNA; proteinAnswer: dFeedback: Genes are not transcribed into polypeptides, protein is not used to synthesize DNA, and messenger RNAs are not translated into tRNAs. RNA can be used to synthesize DNA using reverse transcriptase, but DNA cannot be utilized to make protein.Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?Page: 294–295

14. A gene product can be

a. an enzyme.b. a polypeptide.c. RNA.d. microRNA.e. All of the aboveAnswer: eFeedback: Gene products can be RNAs (such as rRNA, tRNA, and microRNA) as well as enzymes and other polypeptides. Messenger RNA is translated into a gene product, protein.Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 294

15. The enzyme that catalyzes the synthesis of RNA isa. peptidyl transferase.b. DNA polymerase.c. tRNA synthase.d. ribosomal RNA.e. RNA polymerase.Answer: eFeedback: DNA polymerase catalyzes the synthesis of DNA, tRNA synthase covalently attaches amino acids to tRNAs, and ribosomal RNA (peptidyl transferase in the large subunit) catalyzes the formation of the peptide bond during translation.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307

16. A mutation occurs such that a spliceosome cannot remove one of the introns in a gene. What effect will this have on that gene?a. It will have no effect; the gene will be transcribed and translated into protein.b. Transcription will terminate early and the protein will not be made.c. Transcription will proceed, but translation will stop at the site where the intron remains.d. Translation will continue, but a nonfunctional protein will be made.e. Translation will continue and will skip the intron sequence.Answer: dFeedback: When an intron fails to be removed, that noncoding sequence is retained in the RNA within the coding sequence. When this RNA is translated, the protein will likely be nonfunctional due to the insertion of a noncoding sequence within the coding sequence.Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296–298

Application

1. What would be the effect of a deletion of the DNA encoding the targeting sequence for that gene product? (Imagine that this protein was targeted to go to the endoplasmic reticulum and the signal sequence was removed as a result of this deletion.)

Answer: Because the protein lacked its targeting sequence, it would no longer be moved to the mitochondria and would remain in the cytoplasm after it had been translated.Textbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311

2. What would happen if the tRNA synthase for tryptophan added a phenylalanine to the tryptophan tRNAs instead of tryptophan?Answer: If the tRNA synthetase for tryptophan added phenylalanine to the tryptophan tRNAs, whenever a tryptophan codon was read by these tryptophan tRNAs, phenylalanine would be added to the polypeptide. This would create proteins that were nonfunctional, and the cell would die.Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 305

3. Suppose that two different mutant strains of a bacterium are unable to grow on a minimal medium without the addition of the amino acid lysine. Explain how this phenotype might be caused by different mutations in each strain, perhaps on the same gene and perhaps in two different genes.Answer: The mutations in these two strains of bacteria apparently interfere with lysine synthesis. Both mutations might be in the same gene coding for an enzyme necessary for lysine synthesis, but one could be a nonsense mutation in the fifth codon and the other a frame-shift mutation in the twenty-third, for example (the number of mutations that can disable a gene is enormous). If lysine synthesis in this bacterium requires more than one enzyme (as is likely), the two mutations could be in different genes coding for different enzymes. In this case, the phenotypes would not be strictly identical; it should be possible to distinguish the two by trying to grow them on minimal media to which different intermediates in the synthesis of lysine have been added (see Figure 12.1).Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292–293

4. Suppose that two auxotrophic mutants that had been isolated are able to grow when fed the same biochemical intermediate. According to the experiments of Beadle and Tatum, the mutations in each of these auxotrophs should be in the same gene, because they were blocked at the same step in a biochemical pathway. Yet, these two auxotrophs had mutations that mapped in different genes. How do you explain this?Answer: These two genes must encode different polypeptides that are both subunits for the same enzyme in this biochemical pathway.Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292–293

TEXTBOOK SELF-QUIZ

1. Which of the following is not a difference between RNA and DNA?a. RNA has uracil; DNA has thymine.b. RNA has ribose; DNA has deoxyribose.

c. RNA has five bases; DNA has four.d. RNA is a single polynucleotide strand; DNA is a double strand.e. RNA molecules are smaller than human chromosomal DNA molecules.Answer: c

2. Normally, Neurospora can synthesize all 20 amino acids. A certain strain of this mold cannot grow in minimal nutritional medium, but grows only when the amino acid leucine is added to the medium. This straina. is dependent on leucine for energy.b. has a mutation affecting a biochemical pathway leading to the synthesis of carbohydrates.c. has a mutation affecting the biochemical pathways leading to the synthesis of all 20 amino acids.d. has a mutation affecting the biochemical pathway leading to the synthesis of leucine.e. has a mutation affecting the biochemical pathways leading to the syntheses of 19 of the 20 amino acids.Answer: d

3. An mRNA has the sequence 5´-AUGAAAUCCUAG-3´. What is the template DNA strand for this sequence?a. 5´-TACTTTAGGATC-3´b. 5´-ATGAAATCCTAG-3ć. 5´-GATCCTAAAGTA-3´d. 5´-TACAAATCCTAG-3é. 5´-CTAGGATTTCAT-3Ánswer: e

4. The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are calleda. aminoacyl-tRNA synthetases.b. transfer RNAs.c. ribosomal RNAs.d. messenger RNAs.e. ribosomes.Answer: b

5. Which of the following does not occur after eukaryotic mRNA is transcribed?a. Binding of RNA polymerase to the promoterb. Capping of the 5´ endc. Addition of a poly A tail to the 3´ endd. Splicing out of the intronse. Transport to the cytosolAnswer: a

6. Transcriptiona. produces only mRNA.

b. requires ribosomes.c. requires tRNAs.d. produces RNA growing from the 5´ end to the 3´ end.e. takes place only in eukaryotes.Answer: d

7. Which statement about translation is not true?a. Translation is RNA-directed polypeptide synthesis.b. An mRNA molecule can be translated by only one ribosome at a time.c. The same genetic code operates in almost all organisms and organelles.d. Any ribosome can be used in the translation of any mRNA.e. There are both start and stop codons.Answer: b

8. Which statement about RNA is not true?a. Transfer RNA functions in translation.b. Ribosomal RNA functions in translation.c. RNAs are produced by transcription.d. Messenger RNAs are produced on ribosomes.e. DNA codes for mRNA, tRNA, and rRNA.Answer: d

9. The genetic codea. is different for prokaryotes and eukaryotes.b. has changed during the course of recent evolution.c. has 64 codons that code for amino acids.d. has more than one codon for many amino acidse. is ambiguous.Answer: d

10. Which statement about RNA splicing is not true?a. It removes introns.b. It is performed by small nuclear ribonucleoprotein particles (snRNPs).c. It removes the introns at the ribosome.d. It is usually directed by consensus sequences.e. It shortens the RNA molecule.Answer: c

BIOPORTAL DIAGNOSTIC QUIZ (Personalized Study Plan Quiz)(By Richard McCarty)

1. Which of the following is not a difference between gene expression in prokaryotes and eukaryotes?a. There are several different RNA polymerases in both prokaryotes and eukaryotes.b. In eukaryotes, RNA polymerase requires transcription factors or initiation.

c. Prokaryotic genes are often grouped together.d. In eukaryotes, the regulation of several genes at once requires common control elements in each of the genes.e. There is a diversity of eukaryotic polymerases that is reflected in the diversity of eukaryotic promoters.Answer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 1. Remembering

2. RNA polymerases differ from DNA polymerases in thata. RNA polymerases do not require a template.b. RNA polymerases use deoxyribonucleoside triphosphates as substrates.c. DNA polymerases use ribonucleoside triphospates as substrates.d. RNA polymerases do not have a proofreading function.e. only DNA polymerases are processive.Answer: dTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 296Bloom’s Category: 2. Understanding

3. A Neurospora mutant cannot grow unless the amino acid, leucine, is added to its growth medium. This straina. is dependent on leucine metabolism for energy.b. is an auxotroph.c. is a prototroph.d. cannot synthesize any amino acids.e. needs leucine as a growth hormone.Answer: eTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 292–293Bloom’s Category: 2. Understanding

4. Beadle and Tatum proposed the one-gene, one-enzyme hypothesis. Why did this hypothesis have to be modified?a. Some RNAs have catalytic activity.b. Not all proteins are enzymes.c. Some enzymes are made up of more than one polypeptide.d. Not all genes code for enzymes.e. Not all enzymes are coded for by genes.Answer: cTextbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?Page: 294Bloom’s Category: 2. Understanding

5. Which of the following statements about pre-mRNA splicing is false?a. It removes introns.b. It is performed by small nuclear ribonucleoprotein particles (snRNPs).c. It is common in prokaryotes.d. It is directed by consensus sequences.e. It shortens the RNA molecule.Answer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 300–301Bloom’s Category: 1. Remembering

6. Processing of pre-mRNA in eukaryotes involvesa. splicing out exons from the primary transcript.b. adding a poly-A tail to the 5´ end.c. adding a G-cap to the 5´ end.d. scrambling gene sequences.e. transport of the primary transcript to the cytoplasm.Answer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 301–302Bloom’s Category: 2. Understanding

7. Order the four steps in eukaryotic gene expression given below from beginning to end.(1) Pre-mRNA is processed to make mRNA.(2) Ribosomes translate the mRNA message to make proteins.(3) mRNA is transported to the cytoplasm.(4) DNA is used as a template make pre-mRNA.a. 1; 4; 3; 2b. 4; 3; 1; 2c. 4; 1; 3; 2d. 4; 1; 2; 3e. 1; 2; 4; 3Answer: cTextbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?Page: 301–302 and 14.5 How Is RNA Translated into Proteins?Page: 304Bloom’s Category: 2. Understanding

8. Which of the following statements about transfer RNAs (tRNAs) is false?a. tRNAs are the adapter molecules proposed by Crick.b. tRNAs are not specific for the amino acids they bind.c. tRNAs interact with mRNA.d. tRNAs interact with ribsomes.e. ATP is required for the charging of tRNAs with amino acids.Answer b

Textbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 304–305Bloom’s Category: 1. Remembering

9. Ribosomesa. are not found in prokaryotes.b. carry genetic information.c. carry out translation.d. contain RNA only.e. have no role in the fidelity of mRNA and tRNA interactions.Answer: cTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 306Bloom’s Category: 1. Remembering

10. In the elongation stage of translation,a. the message is read from a 3´ to 5´ direction.b. the polypeptide chain grows from a C-terminal to N-terminal direction.c. peptidyl transferase activity is catalyzed by a ribosomal protein.d. rRNA plays a passive role.e. rRNA is catalytically active.Answer: eTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307Bloom’s Category: 1. Remembering

11. At the initiation of translation in eukaryotes,a. the complex of mRNA and the large ribosomal subunit are formed.b. the anticodon of tRNA charged with methionine binds to mRNA associated with the small ribosomal subunit.c. a Shine-Delgarno sequence on the mRNA is involved.d. the large ribosomal subunit binds to the complex before the methionine-charged tRNA.e. the poly A “tail” of mRNA is directly involved.Answer: bTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 307Bloom’s Category: 1. Remembering

12. Termination codonsa. are not part of the genetic code.b. bind tRNAs.c. bind mRNA factor.d. stop translation.e. stop transcription.Answer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?


13. The genetic codea. is considered ambiguous.b. is considered redundant.c. differs among various organisms.d. excludes start and stop codons.e. has only one codon that represents glycine.Answer: bTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 2. Understanding

14. Which of the following single base substitutions in the transcribed strand of DNA would result in premature termination of translation?a. CAA to CAGb. CCT to CCCc. ATG to ATTd. GAG to TAGe. CTG to CTTAnswer: cTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA?Page: 299Bloom’s Category: 4. Analyzing

15. Cells that are making proteins at high ratesa. accumulate free ribosomes.b. accumulate ribosomal subunits.c. are likely to have a single ribosome associated with mRNA.d. are likely to have polysomes.e. make just one copy of a protein from a single mRNA.Answer: dTextbook Reference: 14.5 How Is RNA Translated into Proteins?Page: 308Bloom’s Category: 2. Understanding

16. A protein that is destined to be excreted from the cell that is making ita. has a signal sequence that targets it to the plasma membrane.b. is made solely by ribosomes free in the cytosol.c. has a signal sequence that stops translation and directs the protein and the ribosome to which it is attached to the endoplasmic reticulum.d. is targeted to the endoplasmic reticulum as a soluble protein.e. is targeted directly to lysosomes.

Answer: cTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 310–311Bloom’s Category: 2. Understanding

17. Based on your knowledge of metabolism in eukaryotes and what you have learned from this chapter, predict the intracellular location of the following enzymes: DNA polymerase I; pyruvate kinase; ribulose 1,5-bisphosphate carboxylase/oxygenase; citrate synthase.a. Nucleus; mitochondrion; chloroplast; cytoplasmb. Nucleus; cytoplasm; chloroplast; mitochondrionc. Cytoplasm; chloroplast; mitochondrion; nucleusd. Cytoplasm; chloroplast; nucleus; mitochondrione. Mitochondrion; chloroplast; nucleus, cytoplasmAnswer: bTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 311Bloom’s Category: 4. Analyzing

18. In eukaryotes, the first amino acid in a growing polypeptide chain is always _______ because the only codon for this amino acid is also the _______. This amino acid is not always the first amino acid in a processed protein because of _______.a. methionine; start codon; proteolysisb. methionine; stop codon; proteolysisc. alanine; start codon; glycosylationd. alanine; stop codon; proteolysise. methionine; start codon; glycosylationAnswer: aTextbook Reference: 14.3 How Is the Information Content in DNA Transcribed to Produce RNA? and 14.6 What Happens to Polypeptides after Translation?Page: 299, 312Bloom’s Category: 2. Understanding

19. Posttranslational alterations of proteinsa. can affect the activity of an enzyme.b. may operate in signal transduction.c. include the addition of polysaccharides to proteins.d. include the cleavage of signal sequences.e. All of the aboveAnswer: eTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312–313Bloom’s Category: 1. Remembering

20. Which of the following statement about glycoproteins is true?a. They are common in the cytoplasm of eukaryotic cells.

b. They are formed after translation of the protein in the cytoplasm.c. They may be incorporated into plasma membranes.d. The sugars are added to the proteins solely in the endoplasmic reticulum.e. Sugar addition to proteins has no signaling function.Answer: cTextbook Reference: 14.6 What Happens to Polypeptides after Translation?Page: 312–313Bloom’s Category: 2. Understanding

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Life 9e - garvness.webs.com Test File-Fro… · Web viewChapter 14: From DNA to Protein: Gene Expression. TEST FILE QUESTIONS (By Catherine Ueckert) Multiple Choice. 1. Tuberculosis