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Chapter 14: The Eukaryotic Genome and Its Expression
TEST FILE QUESTIONS
Multiple Choice
1. Cheetahs are very susceptible to disease because
a. they lack genetic diversity.
b. they have many mutated genes.
c. they have many more regulatory proteins compared to prokaryotes.
d. they have very large genomes compared to prokaryotes.
e. much of their DNA is noncoding.
Textbook Reference: 14.0 Endangered Genomes, p. 306
2. Among eukaryotes, there is _______ relationship between complexity and genome
size.
a. an inverse
b. a direct
c. not always an inverse
d. not always a direct
e. no
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
307
3. A lily, which has 18 times more DNA than a human, codes for _______ proteins.
a. more
b. the same number of
c. fewer
d. 337
e. 6,330
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
307
4. If it were stretched out, the DNA from a human cell would be _______ in length.
a. 2 mm
b. 2 m
c. 2 km
d. 2 m
e. None of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
307
5. Human cells have approximately _______ times the amount of DNA found in
prokaryotic cells.
a. 10
b. 100
c. 1,000
d. 10,000
e. 100,000
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
6. In eukaryotic cells, transcription and translation
a. are separated: Translation occurs in the nucleus, and transcription occurs in the
cytoplasm.
b. occur together in the cytosol.
c. occur together in the nucleus.
d. are separated: Translation occurs in the cytoplasm, and transcription occurs in the
nucleus.
e. are separated, except for proteins that bind to the DNA and ribosomes, which are
translated in the nucleus.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? 308
7. Each human chromosome must have
a. a centromeric sequence.
b. telomeric sequences.
c. an origin of replication.
d. All of the above
e. None of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
8. RNA synthesis in eukaryotes occurs
a. solely in mitochondria.
b. primarily in the Golgi apparatus.
c. primarily in the endoplasmic reticulum.
d. primarily in the nucleus.
e. solely in the cytoplasm.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
9. RNA translation in eukaryotes occurs
a. solely in mitochondria.
b. primarily in the Golgi apparatus.
c. primarily in the endoplasmic reticulum.
d. primarily in the nucleus.
e. solely in the cytoplasm.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
10. In bacteria, transcription
a. is separate from translation.
b. occurs in the nucleus.
c. is not separate from translation.
d. is the process of synthesizing proteins.
e. is continuous for all genes.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
11. Caenorhabditis elegans is a
a. yeast.
b. virus.
c. fruit fly.
d. bacterium.
e. roundworm.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
308
12. C. elegans has approximately _______ genes.
a. 19,000
b. 6,000
c. 4,200
d. 3,200
e. 370
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
309
13. The genome size of fruit flies is _______ that of roundworms.
a. about the same as
b. much smaller than
c. much larger than
d. slightly smaller than
e. slightly larger than
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
309
14. The similarity between the human genome and the genome of the puffer fish indicates
that
a. chromosomal rearrangements account for phenotypic differences.
b. humans and puffer fish have a large amount of repetitive DNA.
c. the complexity of an organism is not determined by genes alone.
d. there are more human mRNAs than human genes.
e. alternative splicing may be a key to the levels of complexity in organisms.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
309
15. A striking difference between the yeast genome and that of E. coli is in the number of
genes involved in
a. protein secretion.
b. membrane transport.
c. DNA replication.
d. energy production.
e. metabolism.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
309
16. In comparison to a simple roundworm, Drosophila melanogaster (the fruit fly) has
_______ genes.
a. about the same number of
b. fewer
c. many more
d. a few more
e. an unknown number of
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
310
17. The field of _______ is concerned specifically with the comparison of genome
sequences of different organisms and their related functions.
a. biology
b. genetics
c. cytogenetics
d. comparative genomics
e. All of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
310
18. Arabidopsis thaliana, or shale crest, is a favorite model organism for study because
a. hundreds can grow and reproduce in a small space.
b. it is easy to manipulate.
c. it has a small amount of repetitive DNA.
d. it has a small genome.
e. All of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
310
19. Transposable elements can
a. alter transcription of a gene.
b. cause a mutation.
c. cause gene duplication.
d. All of the above
e. None of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
20. SINEs and LINEs are both
a. highly repetitive DNA sequences.
b. transposable elements.
c. control sequences.
d. retrotransposons.
e. DNA transposons.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
21. DNA transposons
a. work by means of reverse transcriptase.
b. are transcribed but not translated.
c. are also called retrotransposons.
d. move to new locations in the genome without replicating.
e. are circular DNA molecules.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
22. Transposable elements are found in both prokaryotes and eukaryotes. One of the
major differences between the copying of transposable elements in eukaryotes and in
prokaryotes is that in some eukaryotes the elements
a. must be denatured before they can be copied.
b. require an RNA intermediate.
c. are not always copied.
d. do not need an enzyme.
e. None of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
23. Which of the following statements about transposons is true?
a. They provide mobile promoters.
b. They alter gene activities.
c. They provide for genetic change when required.
d. They inactivate unnecessary or undesirable genes.
e. They may contribute to genetic variation.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
24. DNA sequences found in introns provide
a. amino acid sequence information.
b. regulatory information.
c. no known useful information.
d. structure for the gene.
e. alternative DNA splicing possibilities.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
25. 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.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
26. The regions of DNA in a eukaryotic gene that encode a polypeptide product are called
a. enhancers.
b. mRNAs.
c. hnRNAs.
d. exons.
e. leader sequences.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
27. 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
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
28. Which of the following is a promoter?
a. Protein
b. RNA
c. DNA
d. Carbohydrate
e. Enzyme
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
29. The region of a gene that binds RNA polymerase to initiate transcription is
a. an exon.
b. the consensus sequence.
c. heterochromatin.
d. the cap.
e. the promoter.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
30. In eukaryotic cells, promoters are
a. transcribed.
b. transcribed and translated.
c. neither transcribed nor translated.
d. transcribed and then removed.
e. sequences of RNA that are spliced out.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
31. 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
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? pp. 313–
314
32. The theoretical basis for DNA–DNA or DNA–RNA hybridization studies is
a. base complementarity between nucleic acid strands.
b. enzyme action.
c. DNA and RNA looping.
d. Both a and c
e. None of the above
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 314
33. When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops
of double-stranded DNA called
a. retroviruses.
b. introns.
c. exons.
d. transcripts.
e. puffs.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
34. A gene family is a set of genes that over time has changed slightly, extensively, or not
at all. Which of the following statements about all gene families is true?
a. They must always be on the same chromosome.
b. They must always code for the exact same proteins.
c. One copy must retain the original function.
d. They usually differ in their exons because these are coding segments.
e. None of the above
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
35. The different members of the -globin gene family
a. are expressed differently in different tissues.
b. are expressed differently at different times of development.
c. are expressed in the same way in different tissues.
d. are expressed in the same way at different times of development.
e. have no known function.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
36. A set of related genes that encode similar proteins is a(n)
a. pseudogene.
b. intron.
c. gene family.
d. retrovirus.
e. oncogene.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
37. Most gene families probably arose through the process of
a. RNA processing.
b. RNA splicing.
c. DNA methylation.
d. transcriptional regulation.
e. gene duplication.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
38. Which of the following statements about the globin genes is true?
a. Different genes are expressed during different stages of prenatal development.
b. Only one copy is functional.
c. The lengths of the mRNAs are very different for different genes.
d. They are the result of differential posttranscriptional splicing.
e. The transcripts are longer than the coding regions.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
39. 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.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
40. 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.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
41. A posttranscriptional modification of mRNA found in eukaryotes is the
a. 5’ cap.
b. 3’ cap.
c. poly T tail.
d. polyadenylation at the 5’ end.
e. None of the above
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
42. 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
43. 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
44. 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
45. 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
46. 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
47. The methylated guanosine cap that is added to the 5’ end of primary mRNA
a. contains all of 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.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
48. Consensus sequences (short segments of DNA) appear in the transcribed regions 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
49. Energy for RNA splicing comes
a. from the nucleotides in the RNA.
b. from ATP.
c. directly from photosynthesis.
d. from glucose.
e. from the splicing enzyme.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
50. 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.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
51. 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.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
52. Which of the following is not a control mechanism for regulating the amount of
protein synthesized in eukaryotic cells?
a. Transcription regulation
b. DNA amplification
c. Transcript processing
d. Breakdown of the synthesized protein
e. Stabilization of the mRNA
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 318
53. 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
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 318
54. Transcription factors are
a. RNA sequences that bind to RNA polymerase.
b. DNA sequences that regulate transcription.
c. proteins that bind to DNA near the promoter sequence.
d. polysaccharides that bind to the transcripts.
e. factors that bind to enhancers.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
55. The three RNA polymerases of eukaryotes catalyze _______ synthesis.
a. rRNA
b. mRNA
c. tRNA
d. All of the above
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
56. RNA polymerase II by itself cannot bind to the chromosome and initiate transcription.
It can bind and act only after regulatory proteins called _______ factors have been
assembled.
a. translation
b. posttranslation
c. initiation
d. transcription
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? 319
57. The RNA polymerase that produces mRNA molecules in eukaryotic cells is
a. RNA polymerase I.
b. RNA polymerase II.
c. RNA polymerase III.
d. primase.
e. reverse transcriptase.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
58. Which of the following statements about TATA boxes is false?
a. They bind a specific transcription factor.
b. They are found in the region of the promoter.
c. They are part of the intron consensus sequence.
d. They help specify the starting point for transcription.
e. They contain thymine–adenine base pairs.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
59. Transcription of eukaryotic genes requires
a. binding of RNA polymerase to the promoter.
b. binding of several transcription factors.
c. capping of mRNA.
d. Both a and b
e. All of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
60. The TATA box is a(n)
a. sequence close to the promoter region of many genes.
b. square-shaped sequence.
c. enhancer consensus sequence.
d. activator sequence necessary for proper translation.
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
61. Which of the following is a transcription factor?
a. Protein
b. RNA
c. DNA
d. Carbohydrate
e. Enzyme
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
62. Which of the following is not a DNA binding motif?
a. Helix-straight-helix
b. Helix-turn-helix
c. Helix-loop-helix
d. Leucine zipper
e. Zinc finger
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
63. Which of the following is an enhancer?
a. Protein
b. RNA
c. DNA
d. Carbohydrate
e. Enzyme
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
64. In eukaryotic cells, a repressor
a. is made of DNA.
b. binds to the enhancer region to block transcription.
c. is located both upstream and downstream from the promoter.
d. binds to the operator to block RNA polymerase.
e. binds to a silencer to reduce transcription rates.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
65. When an enhancer is bound, it
a. increases the stability of a specific mRNA.
b. stimulates transcription of a specific gene.
c. stimulates transcription of all genes.
d. stimulates splicing of a specific mRNA.
e. stimulates splicing of all mRNAs.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
66. A DNA sequence, which can be distant from the gene, stimulates transcription when
bound by a protein. This sequence is called a(n)
a. TATA box.
b. operon.
c. enhancer.
d. promoter.
e. consensus sequence.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
67. Which of the following statements about -globin production is true?
a. A translational repressor protein binds to the -globin and prevents ribosomes from
attaching.
b. Alternative splicing of pre-mRNA results in the production of several different -
globins.
c. Transcription of the -globin gene is determined by transcription factors, regulators,
enhancers, activators, silencers, and repressors.
d. Ubiquitin forms a complex with the -globin that causes its premature breakdown.
e. The 5’ guanosine cap added to the mRNA is the location where RNA polymerase
initiates transcription.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
68. Coordinated gene expression in eukaryotic cells is possible because
a. one event often leads to another similar event.
b. a transcript codes for more than one protein.
c. of similarities in promoters for different genes.
d. of the universal nature of the genetic code.
e. all promoters are different.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 321
69. The drought stress response in plants is an example of
a. a transcription factor.
b. coordinated gene expression.
c. a way to increase water intake.
d. Both a and b
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 321
70. DNA is wound around histones to form structures that block both the initiation and
elongation steps of transcription. These structures are
a. condensed chromosomes.
b. lampbrush chromosomes.
c. nucleosomes.
d. the solenoid structure of DNA.
e. 30 nm DNA fibers.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 322
71. Several types of histone modification affect gene activation and repression. Cancer
cells are characterized by a greater degree of
a. methylation.
b. phosphorylation.
c. acetylation.
d. interference.
e. deacetylation.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 322
72. Nucleosomes disaggregate to allow transcription and then reaggregate
a. through alternative splicing.
b. by acetylation and deacetylation.
c. through alternation of nucleotides.
d. by attaching ubiquitin.
e. through insertion of nucleotides.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 322
73. A cell that contains three Barr bodies will necessarily have
a. three Y chromosomes.
b. three X chromosomes.
c. four Y chromosomes.
d. four X chromosomes.
e. three nucleoli.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
74. DNA methylation in eukaryotic chromosomes involves adding a methyl to the
a. 5’ position of G.
b. 5’ position of C.
c. proteins bound to the DNA.
d. RNA molecules.
e. ribose.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
75. One of the genes that is known to be transcribed from the inactive X chromosome is
a. Xist.
b. ZIST.
c. inactivation controller protein.
d. lithozist.
e. methyl-X.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
76. Mary Lyon, Liane Russell, and Ernest Beutler discovered
a. the basis of hormone action.
b. X chromosome inactivation.
c. Barr bodies.
d. melanosomes.
e. heterochromatin.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
77. The Barr body is evidence for
a. X chromosome inactivation.
b. cell death.
c. ion pumps.
d. posttranslational control of eukaryotic gene expression.
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
78. If each interphase nucleus in a preparation of normal rat epithelial cells is found to
contain a single Barr body, one can conclude that
a. the cells are in meiotic prophase.
b. all of the chromatin in these cells is inactive.
c. the DNA in these cells has replicated.
d. the cells are not transcribing any genes.
e. the cells came from a female rat.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
79. The interphase cells of normal female mammals have a stainable nuclear body called
a Barr body. This body is
a. an inactive X chromosome.
b. made of fat droplets.
c. made of fragments of mRNA.
d. made of extra chromosomal pieces.
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
80. Heterochromatin
a. contains poly A tails.
b. is rarely transcribed.
c. does not contain any DNA.
d. is not replicated during the S phase.
e. is found only in prokaryotes.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
81. In neurons, the globin gene contains many methylated cytosines. The globin gene,
therefore, is
a. expressed only in males.
b. expressed only in females.
c. not expressed.
d. regulated by posttranscriptional control.
e. regulated by posttranslational control.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
82. A chemical modification that adds methyl groups to cytosine residues in some genes
acts to
a. enhance transcription.
b. amplify the gene.
c. inactivate the gene.
d. stabilize the mRNA.
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
83. DNA methylation
a. is a mechanism of gene inactivation.
b. adds methyl groups to cytosine residues in certain genes.
c. inhibits transcription.
d. Both a and b
e. All of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
84. In fish and frog eggs, _______ increases from 0.2 percent to 68 percent of the total
genomic DNA through selective gene amplification.
a. tRNA
b. rRNA
c. rRNA gene clusters
d. tRNA gene clusters
e. mRNA gene clusters
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 324
85. In some cancers, multiple copies of oncogenes are made and transcribed. This is an
example of
a. gene amplification.
b. DNA methylation.
c. posttranscriptional control.
d. RNA splicing.
e. the assembly of a gene family.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 324
86. Expression of some eukaryotic genes can be regulated by translational control. One
advantage of translational control is that it
a. provides a means for rapid change in protein concentrations.
b. prevents synthesis of excess RNA.
c. directs proteins to their proper subcellular location.
d. occurs only in zygotes.
e. degrades proteins that are no longer needed.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 324
87. The expression of some genes can be regulated in part by the pattern of RNA splicing.
This is an example of
a. DNA methylation.
b. transcriptional regulation.
c. catalytic RNA activity.
d. posttranscriptional control.
e. the endosymbiotic theory.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 325
88. Which of the following statements about the production of tropomyosin is true?
a. A translational repressor protein binds to the tropomyosin mRNA and prevents
ribosomes from attaching.
b. Alternative splicing of pre-mRNA results in the production of several different
proteins.
c. Tropomyosin can recognize and bind to tropomyosin pre-mRNA, causing an
acceleration of its breakdown.
d. Ubiquitin forms a complex with the tropomyosin, which causes its breakdown.
e. The 5’ guanosine cap added to the mRNA is not modified until the mRNA and is
needed.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 325
89. Mature mRNA can be edited by
a. the addition of new nucleotides.
b. methylation.
c. alternative splicing.
d. the attachment of ubiquitin.
e. intron removal.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 326
90. Which of the following statements about the control of protein synthesis in tobacco
hornworms is true?
a. A translational repressor protein binds to the mRNA and prevents ribosomes from
attaching.
b. Alternative splicing of pre-mRNA results in the production of several different
proteins.
c. Proteins can recognize and bind to mRNA, causing an acceleration of its breakdown.
d. Ubiquitin forms a complex with the mRNA, which causes its breakdown.
e. The 5’ guanosine cap added to the mRNA is not modified until the mRNA is needed.
Textbook Reference: 14.6 How Is Gene Expression Controlled During and After
Translation? p. 326
91. Which of the following statements about the control of ferritin synthesis is true?
a. A translational repressor protein binds to the ferritin mRNA and prevents ribosomes
from attaching.
b. Alternative splicing of pre-mRNA results in the production of several different
proteins.
c. Ferritin can recognize and bind to ferritin RNA, causing an acceleration of its
breakdown.
d. Ubiquitin forms a complex with the ferritin, which causes its breakdown.
e. The 5’ guanosine cap added to the mRNA is not modified until the mRNA and is
needed.
Textbook Reference: 14.6 How Is Gene Expression Controlled During and After
Translation? p. 326
92. Transferrin is a protein that transports iron into cells. The iron concentration in a cell
regulates the amount of transferrin protein being made, but it has no effect on the levels
of transferrin mRNA. This is an example of
a. translational control.
b. the function of an enhancer.
c. transcriptional regulation.
d. RNA processing.
e. the function of a promoter.
Textbook Reference: 14.6 How Is Gene Expression Controlled During and After
Translation? p. 326
93. Ubiquitin forms a complex with proteins and then binds with _______, forming a sort
of “molecular chamber of doom.”
a. the extracellular space
b. mitochondria
c. the proteasome
d. lysosomes
e. the Golgi apparatus
Textbook Reference: 14.6 How Is Gene Expression Controlled During and After
Translation? p. 327
94. Some metabolic pathways are regulated in part by changes in the rate of degradation
of key enzymes.
This is an example of
a. operon control.
b. transcriptional control.
c. liquid hybridization.
d. feedback inhibition.
e. posttranslational control.
Textbook Reference: 14.6 How Is Gene Expression Controlled During and After
Translation? p. 327
Fill in the Blank
1. A genome whose protein product and function has been determined is said to be
_______.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
307
2. DNA sequences called _______ can replicate and insert themselves into different parts
of the genome.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
3. Simple sequence repeats, also known as _______, are very short repetitive sequences
scattered through a genome.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
4. Segments of a gene that are transcribed but do not encode part of the protein product
are called _______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
5. In both prokaryotes and eukaryotes, the _______ is a stretch of DNA to which RNA
polymerase binds to
initiate transcription.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
6. DNA sequences present in pre-mRNA but not present in the mature mRNA are
referred to as noncoding base sequences, or _______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
7. A DNA sequence that signals the end of transcription in eukaryotes is called the
_______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
8. Groups of structurally and functionally related genes within a genome are referred to as
_______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
9. A method used to study the relationship between eukaryotic genes and their transcripts
is _______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
10. Members of a gene family that do not make a functional gene product are called
_______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
11. Most _______ are probably duplicate genes that changed so much during evolution
that they no longer function.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
12. During human development, different genes are expressed at different times and in
different tissues. This phenomenon is called _______.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 315
13. During RNA splicing, various snRNPs constitute a “splicing machine” called a
_______.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
14. The RNA of snRNPs are complementary to _______ sequences located at the intron–
exon boundaries.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
15. There are at least three ways in which _______ may be controlled: (1) Genes may be
inactivated; (2) specific genes may be amplified; and (3) specific genes may be selectively
transcribed.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? pp. 318–324
16. DNA in eukaryotes is wrapped around special proteins to form structures that look
like beads on a string. These structures are called _______.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 322
17. In a stained preparation of epithelial cells from a female mammal, the highly
condensed chromosome observable in interphase nuclei is the inactive X chromosome, or
_______.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
18. The gene that codes for an RNAi that binds to Xist RNA at the active X chromosome
is _______.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
19. The process of creating more copies of a gene in order to increase its transcription is
called _______.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 324
Diagram
1.–3. Refer to the graph below to answer the questions that follow.
1. From the graph it can be concluded that
a. different globins are expressed at different times.
b. half of all eukaryotic protein-coding genes exist in only one copy.
c. and are pseudogenes that are a result of mutations.
d. protein-coding genes contain noncoding sequences.
e. RNA can be edited to change the encoded protein.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 316
2. The dominant globin(s) found in a 24-week-old fetus
a. is -globin.
b. is -globin.
c. are -globin and -globin, which are present in equal amounts
d. are -, -, and -globin, present in equal amounts
e. cannot be determined.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 316
3. At about 2 weeks after birth,
a. the amount of -globin increases.
b. the amount of -globin decreases.
c. the amounts of -globin and -globin globin increase.
d. -, -, and -globin are present in equal amounts.
e. -globin and -globin are present in equal amounts.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 316
STUDY GUIDE QUESTIONS
Knowledge and Synthesis Questions
1. Eukaryotic chromosomes
a. are circular and contain origins and terminator sequences.
b. are linear and have origins and telomeres.
c. contain coding and noncoding sequences.
d. Both b and c
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? pp.
307–308
2. Model eukaryotic organisms have helped biologists understand
a. genes involved in development.
b. gene families.
c. genes encoding proteins that are essential for all cells.
d. All of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? pp.
308–311
3. Moderately repetitive DNA includes
a. only coding sequences.
b. only noncoding sequences.
c. coding and noncoding sequences.
d. satellites, minisatellites, and microsatellites.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
4. Transposable genetic elements
a. always affect the cell adversely, because when they move, they inactivate genes.
b. are retroviruses.
c. provide a mechanism for moving genetic material from organelle genomes to the
nuclear genome.
d. always replicate their DNA when they move.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? pp.
311–312
5. Introns are DNA sequences that
a. code for functional domains in proteins.
b. are removed from pre-mRNA by spliceosomes.
c. allow one gene to make different gene products, depending on which introns are
removed during splicing.
d. Both b and c
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? pp. 313–
315
6. Globin genes are
a. introns that are visible using nucleic acid hybridization with DNA and globin mRNA.
b. translationally regulated by excess heme.
c. part of a family of globin genes, with different genes expressed at different times in
development.
d. All of the above
Textbook Reference: 14.2 What are the Characteristics of Eukaryotic Genes? p. 315; 14.5
How Is Eukaryotic Gene Expression Regulated After Translation? p. 326
7. Pre-mRNAs must be processed in the nucleus in order to
a. increase their stability in the cytoplasm.
b. allow RNA polymerase to initiate transcription.
c. permit coding sequences to be joined to adjacent noncoding sequences.
d. facilitate ribosome recognition in preparation for DNA synthesis.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
8. Coordinated regulation of genes in eukaryotic cells
a. is the result of positioning the same regulatory sequence in front of each gene.
b. results from all of those genes being under the control of one promoter.
c. occurs because related genes all have the same operons.
d. occurs because enhancers cause DNA to bend.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? pp. 321–322
9. The transcription complex includes _______ and _______.
a. transcription factors; promoters
b. regulator proteins; regulators
c. repressor proteins; silencers
d. Both a and b
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
10. DNA binding proteins
a. have distinct three-dimensional structures that allow them to bind to the DNA.
b. can be transcription factors.
c. can help condense the DNA in the nucleus.
d. All of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? pp. 320–321
11. Chromatin structure must be altered for gene expression to occur because
a. condensed chromatin is replicated but not transcribed.
b. condensed chromatin makes most DNA sequences inaccessible to the transcription
complex.
c. decondensed chromatin has more nucleosomes per DNA molecule.
d. heterochromatin is actively transcribed and euchromatin is not transcribed.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 322
12. When DNA sequences are moved to new sites on a chromosome,
a. new genes can be transcribed.
b. genes can be inactivated.
c. new genes can be created.
d. All of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312
13. rRNA gene copies are amplified to
a. ensure that gene expression in somatic cells will continue.
b. make more copies of DNA origins for replication.
c. ensure that there is enough translational machinery for the rapid development of the
embryo.
d. help heterochromatin become more accessible to the transcription complex.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 324
14. Posttranscriptional regulation can include
a. binding of repressor on silencer regions.
b. insertion and alteration of nucleotides.
c. decreasing mRNA stability in the cytoplasm.
d. Both b and c
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 325
15. Genes can be inactivated by
a. inaccurate removal of introns.
b. transposable genetic elements.
c. movement of genes to heterochromatic regions of the chromosome.
d. All of the above
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312; 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323; 14.5 How Are
Eukaryotic Genes Processed? p. 317
Application Questions
1. The cells of the lily plant have 18 times more DNA than human cells, yet human DNA
is more complex. Explain this phenomenon.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
2. When normal cells become transformed into cancer cells, gene regulation and
chromosome stability in those cells is altered. Describe three different ways that cancer
cells are different from normal cells.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
312; 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 324; 14.6 How Is Gene
Expression Controlled During and After Translation? p. 327
3. A mutation occurs in the promoter of a eukaryotic gene, eliminating the TATA box.
How will this mutation affect the transcription of this gene?
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
4. A different mutation eliminates the enhancer sequence on the DNA for this gene. How
will this mutation affect the transcription of this gene?
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
5. Describe one posttranscriptional regulatory event and one posttranslational regulatory
event that controls the level of gene expression in eukaryotic cells.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? pp. 324–326; 14.6: How Is Eukaryotic Gene Expression Controlled
During and After Translation? pp. 326–327
ONLINE QUIZ QUESTIONS
1. Regarding genes and gene expression, which of the following is not a difference
between prokaryotes and eukaryotes?
a. Eukaryotic DNA does not contain a TATA box close to the initiation site as does
prokaryotic DNA.
b. In eukaryotes, RNA polymerase requires ‘transcription factors’or initiation.
c. Prokaryotic genes are often grouped together in operons.
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.
Textbook Reference: 14.4 How Is Eukaryotic Gene Expression Regulated After
Transcripton? p. 319
2. The sequence of mRNA can be changed after transcription and splicing by
a. alternative splicing.
b. exsomes.
c. gene amplification.
d. the insertion of new proteins.
e. RNA editing.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 326
3. It has been found that the genomes of humans and Fugu rubripes are similar, yet
humans are much more complex than Fugu rubripes. What can be concluded from this
difference in complexity even though the number and type of genes are similar?
a. Genes alone do not determine the complexity of an organism.
b. Genes play an integral role in determining an organism’s complexity.
c. Humans have small gene families.
d. Fugu rubripes have small gene families.
e. The Fugu rubripes genome contains 177 genes with sequences similar to genes that
also occur in the human genome and are involved in human disease.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
307
4. Which statement about RNA splicing is false?
a. It removes introns.
b. It is performed by small nuclear ribonucleoprotein particles (snRNPs).
c. It always removes the same introns.
d. It is directed by consensus sequences.
e. It shortens the RNA molecule.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 324
5. Processing of pre-mRNA to make mRNA 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 3’ end.
d. the use of splicing to remove coding sequences.
e. using a spliceosome to cut out the introns.
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
6. The functions of the eukaryotic genome include all of the following except
a. enzymes for general metabolism.
b. cell cycle regulation and DNA replication.
c. fertilization.
d. membrane structure and transport.
e. cell signaling.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
309
7. Put the events of eukaryotic transcription and translation in chronological order,
beginning with the first step.
(1) Pre-mRNA is processed and parts are removed to make mRNA.
(2) Ribosomes translate the mRNA into proteins.
(3) mRNA is transported to the cytoplasm.
(4) DNA is used to 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
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
8. Transcription
a. produces only mRNA.
b. uses ribosomes to synthesize DNA.
c. takes place only in prokaryotes.
d. uses triplet codons to make RNA polymerase.
e. is the process of making an RNA copy of DNA.
Section 14.
9. Which of the following are not used in transcriptional regulation in eukaryotes?
a. Enhancers
b. Silencers
c. Transcription factors
d. RNA polymerase subunits
e. Promoters
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
10. Which of the following statements about heterochromatin is false?
a. Heterochromatin contains more DNA than does euchromatin.
b. Methylated DNA appears to bind certain chromosomal proteins that may be
responsible for heterochromatin formation.
c. Heterochromatin is generally not transcribed.
d. An example of heterochromatin is the inactive X chromosome of mammals.
e. Any genes contained in heterochromatin are inactivated.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
11. Which of the following about mRNA translation is false?
a. Most gene products are modified after translation.
b. An mRNA that is capped with an unmodified GTP molecule is always translated.
c. One way to regulate translation is through the G cap.
d. The stability of the mRNA in the cytoplasm can be regulated.
e. An increase in ferritin synthesis is due to an increased rate of mRNA translation.
Textbook Reference: 14.5 How Is Eukaryotic Gene Expression Regulated After
Transcription? p. 324
12. Which of the following statements about eukaryotic protein-coding genes is false?
a. They contain a promoter that binds with an RNA polymerase to begin the transcription
process.
b. They do not require help from another molecule to recognize the promoter.
c. They contain non-coding base sequences called introns.
d. They are single-copy DNA sequences.
e. They form gene families.
Textbook Reference: 14.2 What Are the Characteristics of Eukaryotic Genes? p. 313
13. A Barr body is the result of
a. euchromatin inactivation.
b. inactivation of an entire X chromosome in human females.
c. euchromatin activation.
d. heterochromatin activation.
e. None of the above
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 323
14. snRNP’s
a. bind to sites in a pre-mRNA at or near the intron-exon boundaries.
b. bind to consensus sequences.
c. splice out exons from pre-mRNA.
d. Both a and b
e. Both b and c
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 317
15. Modifications of the ends of the primary RNA transcript of a protein coding gene
include the addition of a
a. 5’ G cap.
b. 3’ G cap.
c. poly A tail to the 5’ end.
d. poly A tail to the 3’ end.
e. Both a and d
Textbook Reference: 14.3 How Are Eukaryotic Gene Transcripts Processed? p. 316
16. Transcription factors in eukaryotes
a. first bind to DNA, allowing RNA polymerase to bind.
b. always repress transcription.
c. are identical at every gene.
d. are always bound to DNA.
e. have only helix-loop-helix domains for DNA binding and recognition.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 319
17. All of the following are potential points for the regulation of gene expression except
a. remodeling of chromatin.
b. mRNA stability control.
c. posttranslational control of protein function.
d. DNA replication.
e. processing control.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 318
18. All of the following are structural motifs of eukaryotic transcription factors except
a. helix-loop-helix.
b. leucine spiral.
c. leucine zipper.
d. zinc finger.
e. helix-turn-helix.
Textbook Reference: 14.4 How Is Eukaryotic Gene Transcription Regulated? p. 320
19. All of the following are types of sequences found in eukaryotic genomes except
a. cosmids.
b. highly repetitive.
c. moderately repetitive.
d. tranposons.
e. minisatellites.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
20. All of the following are types of transposons except
a. retrotransposons.
b. DNA transposons.
c. microtransposons.
d. SINEs.
e. LINEs.
Textbook Reference: 14.1 What Are the Characteristics of the Eukaryotic Genome? p.
311
TEXTBOOK END-OF-CHAPTER QUESTIONS
1. Eukaryotic protein-coding genes differ from their prokaryotic counterparts in that
eukaryotic genes
a. are double-stranded.
b. are present in only a single copy.
c. contain introns.
d. have a promoter.
e. transcribe mRNA.
2. Comparison of the genomes of yeast and bacteria shows that only yeast has many genes
for
a. energy metabolism.
b. cell wall synthesis.
c. intracellular protein targeting.
d. DNA-binding proteins.
e. RNA polymerase.
3. The genomes of the fruit fly and the nematode are similar to that of yeast, except that
the former organisms have many genes for
a. intercellular signaling.
b. synthesis of polysaccharides.
c. cell cycle regulation.
d. intracellular protein targeting.
e. transposable elements.
4. Which of the following does not occur after mRNA is transcribed?
a. Binding of RNA polymerase II to the promoter
d. Splicing out of the introns
e. Transport to the cytosol
5. Which statement about RNA splicing is not true?
a. It removes introns.
b. It is performed by small nuclear ribonucleoprotein particles (snRNPs).
c. It always removes the same introns.
d. It is usually directed by consensus sequences.
e. It shortens the RNA molecule.
6. Eukaryotic transposons
a. always use RNA for replication.
b. are approximately 50 bp long.
c. are made up of either DNA or RNA.
d. do not contain genes coding for transposition.
e. make up about 40 percent of the human genome.
7. Which statement about selective gene transcription in eukaryotes is not true?
a. Different classes of RNA polymerase transcribe different parts of the genome.
b. Transcription requires transcription factors.
c. Genes are transcribed in groups called operons.
d. Both positive and negative regulation occur.
e. Many proteins bind at the promoter.
8. Heterochromatin
a. contains more DNA than does euchromatin.
b. is transcriptionally inactive.
c. is responsible for all negative transcriptional control.
d. clumps the X chromosome in human males.
e. occurs only during mitosis.
9. Translational control
a. is not observed in eukaryotes.
b. is a slower form of regulation than transcriptional control.
c. can be achieved by only one mechanism.
d. requires that mRNA be uncapped.
e. ensures that heme synthesis equals globin synthesis.
10. Control of gene expression in eukaryotes includes all of the following except
a. alternative splicing of RNA transcripts.
b. binding of proteins to DNA.
c. transcription factors.
d. feedback inhibition of enzyme activity by allosteric control.
e. DNA methylation.
ANSWERS
TEST FILE
Multiple Choice
1. a
2. d
3. c
4. b
5. d
6. d
7. d
8. d
9. e
10. c
11. e
12. a
13. c
14. c
15. a
16. b
17. d
18. e
19. d
20. b
21. d
22. c
23. e
24. c
25. b
26. d
27. a
28. c
29. e
30. c
31. d
32. a
33. b
34. c
35. b
36. c
37. e
38. a
39. a
40. a
41. a
42. e
43. e
44. b
45. c
46. c
47. c
48. b
49. b
50. d
51. b
52. d
53. e.
54. c
55. d
56. d
57. b
58. c
59. d
60. a
61. a
62. a
63. c
64. e
65. b
66. c
67. c
68. c
69. b
70. c
71. e
72. b
73. d
74. b
75. a
76. b
77. a
78. e
79. a
80. b
81. c
82. c
83. e
84. c
85. a
86. a
87. d
88. b
89. a
90. e
91. a
92. a
93. c
94. e
Fill in the Blank
1. annotated
2. transposable elements
3. microsatellites
4. introns
5. promoter
6. introns
7. terminator
8. gene families
9. nucleic acid
hybridization
10. pseudogenes
11. pseudogenes
12. differential gene
expression
13. spliceosome
14. consensus
15. transcription
16. nucleosomes
17. Barr body
18. Tsix
19. gene amplification
Diagram
1. a
2. a
3. e
STUDY GUIDE
Knowledge and Synthesis
1. d. Eukaryotic chromosomes are linear, contain origins, telomeres and coding and non
coding sequences. (Prokaryotic chromosomes are circular and contain termination
sequences.)
2. d. Important developmental genes and gene families have been found in several
different eukaryotic organisms. Comparisons of genes in eukaryotes and prokaryotes have
revealed many similar genes that provide the same essential functions to those cells.
3. c. Moderately repetitive sequences include the ribosomal gene clusters as well as
noncoding sequences such as telomeres and Alu sequences. Satellites, minisatellites, and
microsatellites do not contain genes.
4. c. Transposable elements do not always have an adverse effect on genes; sometimes
their insertion can create new genes. Retrotransposons are like retroviruses, but lack the
genes for the viral capsid proteins. DNA transposons do not replicate their DNA before
they move to a different site on the chromosome.
5. d. Introns are removed by spliceosomes, and differential splicing can produce different
gene products as seen in the tropomyosin example (review Figure 14.20).
6. d. The introns in the -globin gene are visible as loops in hybridizations between -
globin DNA and the mRNA for -globin (see Figure 14.6). Globin genes are
translationally regulated by heme, and they are part of the family of globin genes.
7. a. Pre-mRNAs are processed in the nucleus for many reasons (see Figures 14.10 and
14.11), including to increase their stability in the cytoplasm. Transcription by RNA
polymerase precedes pre-mRNA processing. Noncoding sequences (introns) are removed
from the pre-mRNA, not joined to coding sequences (exons). Ribosome recognition does
not lead to DNA synthesis.
8. a. Each eukaryotic gene is transcribed from a separate promoter, and eukaryotic genes
do not have operons to regulate them.
9. d. Transcription complexes include transcription factors bound to the promoter and
regulator proteins bound to regulators. (When repressor proteins are bound to silencers,
transcription is inhibited.)
10. d. DNA binding proteins must have three-dimensional structures appropriate for
binding DNA. Some DNA-binding proteins are transcription factors, some are
telomerases, which bind the ends of chromosomes, and some are nucleosomes, which
bind the DNA and help pack it into the nucleus.
11. b. Nucleosomes condense the DNA. Heterochromatin is transcriptionally inactive,
whereas euchromatin is transcriptionally active.
12. d. Transposable elements can be transcribed if they move adjacent to a promoter.
Transposable elements can inactivate a gene if they insert into the middle of a coding
sequence. Transposable elements can move parts of genes with them to new
chromosomal sites, potentially creating new genes.
13. c. Ribosomal RNA amplification occurs in the eggs of fishes and frogs to prepare for
the rapid development and protein synthesis that immediately follows fertilization.
Amplified rRNA is not needed in somatic cells, DNA origins or for accessibility to the
chromosome.
14. d. Repressors that bind at silencer sequences regulate transcription and thus are not
posttranscriptional mechanisms of regulation.
15. d. Inaccurate removal of introns can create mRNAs that are missing coding sequence
or that have extra noncoding sequences. Transposable genetic elements can move into the
coding regions of genes, inactivating those gene products. Moving a gene to a hetero-
chromatic (transcriptionally inactive) region of a chromosome results in that DNA being
inaccessible to the transcription complex.
Application
1. The DNA of the lily plant must contain more noncoding and repetitive sequences and
less coding sequence than human DNA.
2. Genetic changes can make a normal cell into a cancerous cell in the following ways: a
transposable element can move into the coding sequence of a gene that regulates cell
division, inactivating that gene, amplification of oncogenes can transform normal cells
into cancer cells, targeting proteins that control cell division for proteasome degradation
(as seen in human papilloma virus and p53) will cause cells to become cancerous.
3. If the TATA box of the promoter for a eukaryotic gene is deleted, transcription factor
TFIID will not bind the promoter. The transcription complex will not assemble at the
promoter and there will be no initiation of transcription.
4. If the enhancer for a gene is deleted, transcription for that gene will still occur, but at a
reduced rate.
5. Posttranscriptional regulatory events can include events that affect splicing, mRNA
stability and inhibition of translation by microRNAs. Posttranslational events can include
modifying the G cap so that the mRNA will be translated and protein degraded.
ONLINE QUIZ
1. a
2. e
3. a
4. c
5. e
6. c
7. c
8. e
9. d
10. a
11. b
12. b
13. b
14. d
15. e
16. a
17. d
18. b
19. a
20. c
TEXTBOOK END-OF-CHAPTER
1. c
2. c
3. a
4. a
5. c
6. c
7. c
8. b
9. e
10. d