Question 1

The level of genetic control that involves the life span of the mRNA molecule and the ability of the mRNA to bind to ribosomes is __________ control.

Accepted Answer

A)   feedback
B)   translational
C)   transcriptional
D)   posttranscriptional
E)   posttranslationalF) B) and E)
G) C) and E)

Question 2

Identify which of the operon elements plays the most critical role in determining gene regulation in prokaryotes.

Accepted Answer

Answers may vary. The operon elements sh...

Question 3

All genes are active at the same time in a prokaryotic cell and controlled by positive regulation, but not in a eukaryotic cell.

Accepted Answer

A) True 
 B)False

Question 4

In the transcription of DNA, remodeling proteins push the histone portion of the nucleosome aside so that transcription may begin.

Accepted Answer

A) True 
 B)False

Question 5

Transposons

Accepted Answer

A)   are specific DNA sequences that move within and between chromosomes.
B)   alter the expression of neighboring genes especially if the transposon is a regulator gene.
C)   have been discovered in corn, fruit flies, bacteria, and humans.
D)   All of the choices are correct.E) A) and B)
F) None of the above

Question 6

The universal regulatory mechanism in eukaryotes for controlling gene expression includes

Accepted Answer

A)   control of the genes transcribed and the rate they are transcribed.
B)   control of the processing of mRNA after it is transcribed from DNA but before it leaves the nucleus, and control of the rate it leaves the nucleus.
C)   control of mRNA in the cytoplasm after it leaves the nucleus, including changes to mRNA before translation begins.
D)   control of polypeptides after they have been synthesized but before they are functional.
E)   All of these mechanisms are used; there is no single universal mechanism.F) B) and C)
G) A) and D) E

Question 7

A form of gene regulation that occurs while RNA is still in the nucleus is

Accepted Answer

A)   differential intron removal and exon splicing.
B)   feedback control.
C)   enzymatic cleavage of a polypeptide.
D)   rate of binding to ribosomes.E) None of the above
F) All of the above

Question 8

Identify the major tumor suppressor gene that is more frequently mutated in human cancers than any other known gene.

Accepted Answer

A)   p53 gene
B)   hemoglobin gene
C)   ras oncogene
D)   p16
E)   RB tumor-repressor geneF) A) and B)
G) D) and E)

Question 9

The regulator gene codes for the DNA-binding proteins that act as repressors.

Accepted Answer

A) True 
 B)False  True

Question 10

Which of the following is a method of posttranscriptional control?

Accepted Answer

A)   transcription factors
B)   the life span of a mRNA molecule
C)   differential processing of mRNA
D)   how fast the mRNA leaves the nucleus
E)   Both C and D are methods of posttranscriptional control.F) A) and D)
G) C) and D)

Question 11

A Barr body

Accepted Answer

A)   is only found in male cells.
B)   is an inactive Y chromosome that produces reduced amount of gene products.
C)   is an inactive X chromosome that does not produce gene products.
D)   All of the choices are correct.E) B) and C)
F) B) and D)

Question 12

One third of all cancer deaths are due to mutations that arise from smoking tobacco.

Accepted Answer

A) True 
 B)False

Question 13

A deletion of one base pair that alters the sequence of codons is called a(n)

Accepted Answer

A)   transposon.
B)   substitution mutation.
C)   carcinogen.
D)   oncogene.
E)   frameshift mutation.F) B) and C)
G) A) and E)

Question 14

The genes of a single operon are all regulated by the same repressor, operator, and promoter.

Accepted Answer

A) True 
 B)False

Question 15

Thymine dimers

Accepted Answer

A)   form when DNA is exposed to carcinogens such as tobacco smoke.
B)   are rarely removed by DNA repair enzymes.
C)   form when DNA is exposed to UV radiation.
D)   result in abnormal protein structure which causes red blood cells to sickle.E) B) and C)
F) A) and B)

Question 16

A much larger percentage of the population is now living to be 80-90 years old than was the case in prehistoric times, when most evolutionary selection for our physiology occurred. Why does cancer seem to loom as a much larger problem today than a century ago?

Accepted Answer

Answers may vary. There is currently muc...

Question 17

"Jumping genes" that have the ability to move within and between chromosomes are called

Accepted Answer

A)   introns.
B)   oncogenes.
C)   transposons.
D)   retroviruses.
E)   exons.F) C) and E)
G) None of the above C

Question 18

What complications could arise if an individual had a genetic disorder that prevented them from forming 25% of their histones?

Accepted Answer

A)   The chromatin would not condense properly and some of it would not be available for transcriptional machinery resulting in the expression of additional genes.
B)   The chromatin would not condense properly and some of it would not be available for transcriptional machinery resulting in the decreased expression of their genes.
C)   The chromatin would condense more than normal and result in the expression of additional genes.
D)   The chromatin would condense more than normal and result in the expression of fewer than normal genes.E) None of the above
F) B) and D)

Question 19

If CAP is absent from a cell what are the potential consequences?

Accepted Answer

A)   The individual cannot activate the catabolism of various other metabolites in the absence of glucose.
B)   The individual does not have a backup system for survival when glucose is absent.
C)   The individual will most likely die because they cannot metabolize enough energy if glucose is absent.
D)   All of these are consequences of the absence of CAP.E) B) and D)
F) All of the above

Question 20

Mutagens and carcinogens are associated with

Accepted Answer

A)   induced mutations.
B)   spontaneous mutations.
C)   transposon activity.
D)   DNA replication errors.E) A) and B)
F) B) and C)

Exam 13: Regulation of Gene Expression

The level of genetic control that involves the life span of the mRNA molecule and the ability of the mRNA to bind to ribosomes is __________ control.

Correct AnswerverifiedShow Answer

Identify which of the operon elements plays the most critical role in determining gene regulation in prokaryotes.

Correct AnswerverifiedAnswers may vary. The operon elements sh...View AnswerShow Answer

All genes are active at the same time in a prokaryotic cell and controlled by positive regulation, but not in a eukaryotic cell.

Correct AnswerverifiedShow Answer

In the transcription of DNA, remodeling proteins push the histone portion of the nucleosome aside so that transcription may begin.

Correct AnswerverifiedShow Answer

Transposons

Correct AnswerverifiedShow Answer

The universal regulatory mechanism in eukaryotes for controlling gene expression includes

Correct AnswerverifiedE

A form of gene regulation that occurs while RNA is still in the nucleus is

Correct AnswerverifiedShow Answer

Identify the major tumor suppressor gene that is more frequently mutated in human cancers than any other known gene.

Correct AnswerverifiedShow Answer

The regulator gene codes for the DNA-binding proteins that act as repressors.

Correct AnswerverifiedTrue

Which of the following is a method of posttranscriptional control?

Correct AnswerverifiedShow Answer

A Barr body

Correct AnswerverifiedShow Answer

One third of all cancer deaths are due to mutations that arise from smoking tobacco.

Correct AnswerverifiedShow Answer

A deletion of one base pair that alters the sequence of codons is called a(n)

Correct AnswerverifiedShow Answer

The genes of a single operon are all regulated by the same repressor, operator, and promoter.

Correct AnswerverifiedShow Answer

Thymine dimers

Correct AnswerverifiedShow Answer

A much larger percentage of the population is now living to be 80-90 years old than was the case in prehistoric times, when most evolutionary selection for our physiology occurred. Why does cancer seem to loom as a much larger problem today than a century ago?

Correct AnswerverifiedAnswers may vary. There is currently muc...View AnswerShow Answer

"Jumping genes" that have the ability to move within and between chromosomes are called

Correct AnswerverifiedC

What complications could arise if an individual had a genetic disorder that prevented them from forming 25% of their histones?

Correct AnswerverifiedShow Answer

If CAP is absent from a cell what are the potential consequences?

Correct AnswerverifiedShow Answer

Mutagens and carcinogens are associated with

Correct AnswerverifiedShow Answer

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E

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True

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Answers may vary. There is currently muc...
View Answer

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C

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