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Life: The Science of Biology, Ninth Edition
Sadava • 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 antibiotics
a. 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: b
Textbook Reference: 14.0 An unexpected wedding gift
Page: 290–291
Bloom’s Category: 3. Applying
2. Genetic material is composed of
a. DNA.
b. amino acids.
c. ribose.
d. carbohydrates.
e. lipids.
Answer: a
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 291
Bloom’s Category: 1. Remembering
3. The major phenotypic expression of genotype is in
a. proteins.
b. tRNA.
c. mRNA.
d. nucleic acids.
e. rRNA.
Answer: a
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 291
Bloom’s Category: 1. Remembering
4. Which of the following are model organisms used in biological research?
a. Pea plants
b. Fruit flies
c. E. coli
d. Bread mold
e. All of the above
Answer: e
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 292
Bloom’s Category: 1. Remembering
5. After irradiating Neurospora, Beadle and Tatum collected mutants that would
a. 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 above
Answer: a
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 293
Bloom’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 that
a. 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: b
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 293
Bloom’s Category: 4. Analyzing
7. The study of Neurospora mutants grown on various supplemented media led to
a. 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 b
e. Both a and c
Answer: d
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 293
Bloom’s Category: 2. Understanding
8. The classic work of Beadle and Tatum, later refined by others, provided evidence for
the
a. 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 above
Answer: e
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 293–294
Bloom’s Category: 2. Understanding
9. Genes code for
a. enzymes.
b. polypeptides.
c. RNA.
d. All of the above
e. None of the above
Answer: d
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 294
Bloom’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 above
Answer: a
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
11. Which of the following molecules transfers information from the nucleus to the
cytoplasm?
a. DNA
b. mRNA
c. tRNA
d. Proteins
e. Lipids
Answer: b
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
12. The link between mRNA and a protein is
a. tRNA.
b. a promoter.
c. RNA polymerase.
d. DNA polymerase.
e. a start codon.
Answer: a
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
13. Which of the following molecules transfers information from mRNA to protein?
a. DNA
b. mRNA
c. tRNA
d. Proteins
e. Lipids
Answer: c
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 1. Remembering
14 The “central dogma” of molecular biology states that
a. 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: c
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
15. The adapters that allow translation of the four-letter nucleic acid language into the 20letter protein language are called
a. aminoacyl tRNA synthetases.
b. transfer RNAs.
c. ribosomal RNAs.
d. messenger RNAs.
e. ribosomes.
Answer: b
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
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 above
Answer: d
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294–295
Bloom’s Category: 2. Understanding
17. Gene expression can be regulated
a. before transcription.
b. during transcription and before translation.
c. during translation.
d. after translation.
e. All of the above
Answer: e
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294–295
Bloom’s Category: 2. Understanding
18. Single-stranded RNA replicates by
a. 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: a
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 295
Bloom’s Category: 2. Understanding
19. Which of the following does (do) not follow the “central dogma”?
a. Yeast
b. Onion cells
c. Bread mold
d. Skin cells
e. Retroviruses
Answer: e
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 295–296
Bloom’s Category: 2. Understanding
20. Retroviruses do not follow the “central dogma” of DNA →
protein
because they
a. 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: a
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 295–296
Bloom’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 called
a. bacteriophage.
b. retroviruses.
c. RNA viruses.
d. DNA viruses.
e. enveloped viruses.
Answer: b
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 296
Bloom’s Category: 1. Remembering
22. Transcription is the process of
a. 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: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 1. Remembering
23. The process of transcription synthesizes
a. transfer RNA.
b. messenger RNA.
c. ribosomal RNA.
d. proteins.
e. a, b, and c
Answer: e
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 2. Understanding
24. The region of DNA in prokaryotes to which RNA polymerase binds most tightly is
the
a. promoter.
b. poly C center.
c. enhancer.
d. operator site.
e. minor groove.
Answer: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 2. Understanding
25. Promoters are made of
a. proteins.
b. carbohydrates.
c. lipids.
d. nucleic acids.
e. amino acids.
Answer: d
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’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: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 1. Remembering
27. RNA polymerase is
a. 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: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’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: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 2. Understanding
29. In bacteria, there is/are _______ RNA polymerase(s) that catalyze the synthesis of
RNA from DNA.
a. one
b. three
c. four
d. five
e. six
Answer: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’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 5´
c. 5´ to 3´; 3´ to 5´
d. 3´ to 5´; 5´ to 3´
e. Examples of all of the above have been found.
Answer: d
Textbook 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 5´
c. 3´ to 5´; 5´ to 3´
d. 3´ to 5´; 3´ to 5´
e. 5´ to 5´; 3´ to 3´
Answer: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 297
Bloom’s Category: 4. Analyzing
32. Errors in transcription are not as potentially harmful as errors in DNA replication
because
a. 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 correct
e. a, b, and c are correct
Answer: d
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’s Category: 2. Understanding
33. The process of transcription requires
a. 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: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’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 that
a. 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 above
Answer: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’s Category: 2. Understanding
35. Termination of transcription involves a
a. stop codon.
b. terminator sequence.
c. termiproteator.
d. hairline slip.
e. series of As.
Answer: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’s Category: 1. Remembering
36. There are _______ different RNA polymerases in eukaryotes.
a. two
b. three
c. four
d. five
e. six
Answer: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’s Category: 1. Remembering
37. The termination of transcription is signaled by
a. the stop codon.
b. a sequence of nitrogenous bases.
c. a protein bound to a certain region of DNA.
d. rRNA.
e. tRNA.
Answer: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’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. 4
b. 8
c. 16
d. 32
e. 64
Answer: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298
Bloom’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 above
Answer: e
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 298–299
Bloom’s Category: 4. Analyzing
40. The stop codons code for
a. no amino acid.
b. methionine.
c. glycine.
d. halt enzyme.
e. DNA binding protein.
Answer: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’s Category: 2. Understanding
41. How many codons specify amino acids?
a. 20
b. 23
c. 45
d. 60
e. 61
Answer: e
Textbook 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 as
a. redundant but not ambiguous.
b. ambiguous but not redundant.
c. both ambiguous and redundant.
d. neither ambiguous nor redundant.
e. nonsense.
Answer: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’s Category: 1. Remembering
43. The three codons in the genetic code that do not specify amino acids are called
a. missense codons.
b. start codons.
c. stop codons.
d. promoters.
e. initiator codons.
Answer: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’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-5´
c. 3´-CAG, GGU-5´
d. 5´-CAG, GGU-3´
e. 5´-CAG, GGT-3´
Answer: d
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’s Category: 3. Applying
45. Poly uracil codes for
a. 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: 299
Bloom’s Category: 1. Remembering
46. Exons are
a. translated.
b. found in most prokaryotic genes.
c. removed during RNA processing.
d. Both a and b
e. Both a and c
Answer: a
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 300
Bloom’s Category: 2. Understanding
47. Exons are
a. 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: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 300
Bloom’s Category: 2. Understanding
48. The regions of DNA in a eukaryotic gene that contain noncoding base sequences are
called
a. enhancers.
b. mRNAs.
c. hnRNAs.
d. introns.
e. leader sequences.
Answer: d
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 300
Bloom’s Category: 1. Remembering
49. Nucleic acid hybridization
a. 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 above
Answer: e
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 301
Bloom’s Category: 1. Remembering
50. When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops
of double-stranded DNA, which are
a. retroviruses.
b. introns.
c. exons.
d. transcripts.
e. puffs.
Answer: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 301
Bloom’s Category: 2. Understanding
51. The tail added to pre-mRNA is
a. coded for by DNA.
b. composed of poly T.
c. important for mRNA stability.
d. attached to its 5´ end.
e. All of the above
Answer: c
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302
Bloom’s Category: 2. Understanding
52. The guanosine triphosphate (GTP) cap that is added to the 5´ end of primary mRNA
a. 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: c
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302
Bloom’s Category: 2. Understanding
53. The modified G cap on eukaryotic mRNAs is found
a. at the 5´ end.
b. at the 3´ end.
c. in the consensus sequence.
d. in the poly A tail.
e. in snRNA.
Answer: a
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302
Bloom’s Category: 1. Remembering
54. Poly A tails
a. 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: a
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302
Bloom’s Category: 1. Remembering
55. Chromosomes of eukaryotic DNA must have
a. 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 above
Answer: c
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302
Bloom’s Category: 2. Understanding
56. Which of the following is not part of RNA processing in eukaryotes?
a. Splicing of exons
b. Reverse transcription
c. Addition of a 5´ cap
d. Addition of a poly A tail
e. Intron removal
Answer: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302–303
Bloom’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 introns
b. Binding of snRNPs, transporting, synthesizing of ribose
c. Capping, transporting, synthesizing of ribose
d. Binding of snRNPs, capping, splicing
e. Splicing, capping, addition of a poly A tail
Answer: e
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302–303
Bloom’s Category: 2. Understanding
58. RNA processing in eukaryotes involves the
a. addition of a G cap.
b. addition of a poly A tail.
c. removal of introns.
d. splicing of exons.
e. All of the above
Answer: e
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 302–303
Bloom’s Category: 2. Understanding
59. snRNPs are
a. 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: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 303
Bloom’s Category: 1. Remembering
60. The binding of snRNPs to consensus sequences is necessary for
a. gene duplication.
b. the addition of a poly A tail.
c. capping an hnRNA.
d. RNA splicing.
e. transcription.
Answer: d
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 303
Bloom’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 in
a. 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 above
Answer: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 303
Bloom’s Category: 2. Understanding
62. The conformation of tRNA is maintained by
a. peptide bonds.
b. hydrogen bonds.
c. disulfide bridges.
d. phosphodiester bonds.
e. glycosidic linkages.
Answer: b
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 303
Bloom’s Category: 2. Understanding
63. Activating enzymes
a. 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 above
Answer: e
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 303
Bloom’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 b
e. All of the above
Answer: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’s Category: 2. Understanding
65. A sequence of three RNA bases can function as
a. a codon.
b. an anticodon.
c. a gene.
d. Both a and b
e. Both a and c
Answer: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’s Category: 2. Understanding
66. The difference between mRNA and tRNA is that
a. 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 b
e. None of the above
Answer: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’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: b
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’s Category: 2. Understanding
68. Fewer different tRNA molecules exist than might have been expected for the
complexity of its function. This is possible because
a. 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: a
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 305
Bloom’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: e
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 305
Bloom’s Category: 2. Understanding
70. The enzyme that charges the tRNA molecules with appropriate amino acids is
a. tRNA chargeatase.
b. amino tRNA chargeatase.
c. transcriptase.
d. aminoacyl-tRNA synthetase.
e. None of the above
Answer: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 305
Bloom’s Category: 1. Remembering
71. Ribosomes are a collection of _______ that are needed for _______.
a. small proteins; translation
b. proteins and small RNAs; translation
c. proteins and tRNAs; transcription
d. proteins and mRNAs; translation
e. mRNAs and tRNAs; translation
Answer: b
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 306
Bloom’s Category: 2. Understanding
72. During translation initiation, the first site occupied by a charged tRNA is the
a. A site.
b. B site.
c. large subunit.
d. T site.
e. P site.
Answer: a
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 306
Bloom’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 by
a. the large ribosomal subunit.
b. a specialized segment of DNA.
c. a specialized segment of RNA.
d. the initiation complex.
e. initiation factors.
Answer: a
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 307
Bloom’s Category: 2. Understanding
74. During translation elongation, the existing polypeptide chain is transferred to
a. 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 above
Answer: b
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 307
Bloom’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 terminus
b. 3´ to 5´; C terminus to N terminus
c. 5´ to 3´; C terminus to N terminus
d. 3´ to 5´; N terminus to C terminus
e. Examples of all of the above have been found.
Answer: a
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 307
Bloom’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 3´
c. C terminus to N terminus; 3´ to 5´
d. N terminus to C terminus; 3´ to 5´
e. N terminus to N terminus; 5´ to 5´
Answer: a
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 308
Bloom’s Category: 2. Understanding
77. In protein synthesis, the endoplasmic reticulum
a. 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: c
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 311
Bloom’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: a
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 311
Bloom’s Category: 4. Analyzing
79. In eukaryotes, ribosomes become associated with endoplasmic reticulum membranes
when
a. 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: d
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 311
Bloom’s Category: 2. Understanding
80. The addition of sugar residues to the protein after translation is called
a. glycation.
b. glycosylation.
c. phosphorylation.
d. proteolysis.
e. exonuclease digestion.
Answer: b
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312
Bloom’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. glycation
b. glycosylation
c. phosphorylation
d. proteolysis
e. exonuclease digestion
Answer: d
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312
Bloom’s Category: 2. Understanding
82. In eukaryotic cells, proteins that contain covalently attached sugar residues are
translated
a. in the nucleus.
b. in the cytoplasm.
c. in mitochondria.
d. on the endoplasmic reticulum.
e. on the Golgi apparatus.
Answer: d
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312
Bloom’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 threedimensional structures will no longer bind to the antibiotic. This phenomenon is known
as _______.
Answer: antibiotic resistance
Textbook Reference: 14.0 An unexpected wedding gift
Page: 290
Bloom’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: model
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 292
Bloom’s Category: 1. Remembering
3. Certain agents, such as X rays, that are known to cause mutations are referred to as
_______.
Answer: mutagens
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 292
Bloom’s Category: 1. Remembering
4. Prototrophs (“original eaters”) grow on minimal media, whereas _______ (“increased
eaters”) require specific additional nutrients.
Answer: auxotrophs
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 292
Bloom’s Category: 2. Understanding
5. The one-gene, one-enzyme hypothesis resulted from the work of _______.
Answer: Beadle and Tatum
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 293
Bloom’s Category: 1. Remembering
6. RNA differs from DNA in base composition in that it contains _______ instead of
thymine.
Answer: uracil
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294
Bloom’s Category: 2. Understanding
7. The basic units of both DNA and RNA molecules are the _______.
Answer: nucleotides
Textbook Reference: 14.2 How Does Information Flow from Genes to Proteins?
Page: 294–295
Bloom’s Category: 1. Remembering
8. The strand of DNA that is transcribed into RNA is the _______ strand.
Answer: template
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 1. Remembering
9. The synthesis of DNA from RNA is called _______.
Answer: reverse transcription
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 1. Remembering
10. The excess of codons (64) over amino acids (20) indicates that the genetic code is
_______.
Answer: redundant
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’s Category: 2. Understanding
11. A noncoding base sequence found in eukaryotic cells is called a(n) _______.
Answer: intron
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 300
Bloom’s Category: 1. Remembering
12. The portion of the tRNA molecule that complementary base-pairs with the mRNA is
called the _______.
Answer: anticodon
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’s Category: 1. Remembering
13. The fact that some tRNA molecules do not have to pair exactly is called _______.
Answer: wobble
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 305
Bloom’s Category: 1. Remembering
14. A tRNA that has bonded to an amino acid is referred to as _______ tRNA.
Answer: charged
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 305
Bloom’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-assembly
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 306
Bloom’s Category: 2. Understanding
16. An mRNA molecule with several ribosomes attached is called a(n) _______.
Answer: polysome
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 308
Bloom’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: signal
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 310
Bloom’s Category: 2. Understanding
18. The addition of phosphate groups to polypeptide chains following translation is called
_______.
Answer: phosphorylation
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312
Bloom’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: c
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 304
Bloom’s Category: 2. Understanding
STUDY GUIDE QUESTIONS
(By Nancy Guild)
Knowledge and Synthesis
1. Transcription in prokaryotic cells
a. 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: c
Feedback: 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: b
Feedback: 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; C
b. 5´-to-3´; N; C
c. 3´-to-5´
d. 5´-to-3´; C; N
e. 3´-to-5´; C; C
Answer: b
Feedback: 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. 16
b. 64
c. 8
d. 32
e. 128
Answer: a
Feedback: 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 – 5´
a. NH2 met—lys—phe—leu—stop COOH
b. NH2 met—lys—phe—trp—stop COOH
c. NH2 asp—gly—phe—lys—val COOH
d. NH2 met—gly—phe—lys—val COOH
e. NH2 asp—gly—phe—lys—stop COOH
Answer: b
Feedback: 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: d
Feedback: 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 – 3´
a. Polyphenylalanine
b. Isoleucine–tyrosine–isoleucine–tyrosine
c. Isoleucine–isoleucine–isoleucine–isoleucine
d. Tyrosine–tyrosine–tyrosine–tyrosine
e. Aspargine–aspargine–aspargine–aspargine
Answer: b
Feedback: 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 attached
b. The 5´ end
c. The anticodon
d. The start codon
e. The promoter
Answer: c
Feedback: 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 an
a. 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 d
Answer: e
Feedback: 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 requires
a. 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 would
a. 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: c
Feedback: 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 that
a. 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: b
Feedback: 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 product
b. protein; DNA; RNA
c. DNA; mRNA; tRNA
d. DNA; RNA; protein
e. RNA; DNA; protein
Answer: d
Feedback: 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 above
Answer: e
Feedback: 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 is
a. peptidyl transferase.
b. DNA polymerase.
c. tRNA synthase.
d. ribosomal RNA.
e. RNA polymerase.
Answer: e
Feedback: 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: d
Feedback: 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 non-coding 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 non-sense 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 strain
a. 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-3´
c. 5´-GATCCTAAAGTA-3´
d. 5´-TACAAATCCTAG-3´
e. 5´-CTAGGATTTCAT-3´
Answer: e
4. The adapters that allow translation of the four-letter nucleic acid language into the 20letter protein language are called
a. 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 promoter
b. Capping of the 5´ end
c. Addition of a poly A tail to the 3´ end
d. Splicing out of the introns
e. Transport to the cytosol
Answer: a
6. Transcription
a. 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 code
a. 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 acids
e. 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: a
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 1. Remembering
2. RNA polymerases differ from DNA polymerases in that
a. 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: d
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 296
Bloom’s Category: 2. Understanding
3. A Neurospora mutant cannot grow unless the amino acid, leucine, is added to its
growth medium. This strain
a. 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: e
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 292–293
Bloom’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: c
Textbook Reference: 14.1 What Is the Evidence that Genes Code for Proteins?
Page: 294
Bloom’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: c
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 300–301
Bloom’s Category: 1. Remembering
6. Processing of pre-mRNA in eukaryotes involves
a. 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: c
Textbook Reference: 14.4 How Is Eukaryotic DNA Transcribed and the RNA Processed?
Page: 301–302
Bloom’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; 2
b. 4; 3; 1; 2
c. 4; 1; 3; 2
d. 4; 1; 2; 3
e. 1; 2; 4; 3
Answer: c
Textbook 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: 304
Bloom’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: 304–305
Bloom’s Category: 1. Remembering
9. Ribosomes
a. 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: c
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 306
Bloom’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: e
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 307
Bloom’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: b
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 307
Bloom’s Category: 1. Remembering
12. Termination codons
a. are not part of the genetic code.
b. bind tRNAs.
c. bind mRNA factor.
d. stop translation.
e. stop transcription.
Answer: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 308
Bloom’s Category: 1. Remembering
13. The genetic code
a. 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: b
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’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 CAG
b. CCT to CCC
c. ATG to ATT
d. GAG to TAG
e. CTG to CTT
Answer: c
Textbook Reference: 14.3 How Is the Information Content in DNA Transcribed to
Produce RNA?
Page: 299
Bloom’s Category: 4. Analyzing
15. Cells that are making proteins at high rates
a. 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: d
Textbook Reference: 14.5 How Is RNA Translated into Proteins?
Page: 308
Bloom’s Category: 2. Understanding
16. A protein that is destined to be excreted from the cell that is making it
a. 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: c
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 310–311
Bloom’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; cytoplasm
b. Nucleus; cytoplasm; chloroplast; mitochondrion
c. Cytoplasm; chloroplast; mitochondrion; nucleus
d. Cytoplasm; chloroplast; nucleus; mitochondrion
e. Mitochondrion; chloroplast; nucleus, cytoplasm
Answer: b
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 311
Bloom’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; proteolysis
b. methionine; stop codon; proteolysis
c. alanine; start codon; glycosylation
d. alanine; stop codon; proteolysis
e. methionine; start codon; glycosylation
Answer: a
Textbook 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, 312
Bloom’s Category: 2. Understanding
19. Posttranslational alterations of proteins
a. 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 above
Answer: e
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312–313
Bloom’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: c
Textbook Reference: 14.6 What Happens to Polypeptides after Translation?
Page: 312–313
Bloom’s Category: 2. Understanding