Question 1

Unlike processing of the primary transcript, RNA editing occurs at the level of mRNA.

Accepted Answer

A) True 
 B)False

Question 2

Methylation is a mechanism often used by cells to prevent the expression of:

Accepted Answer

A)  genes in transposable elements.
B)  genes from viruses that have been integrated into the genome.
C)  harmful (mutant) genes such as those responsible for cystic fibrosis.D) B) and C)
E) A) and B)

Question 3

Certain genes have apparently unusual inheritance patterns. For instance, in the mouse autosomal gene H19, only the copy inherited from the mouse's mother is expressed. Conversely, in the mouse autosomal gene Igf2, only the copy inherited from the mouse's father is expressed. The consequence of this is that imprinted genes are expressed as if they were present in only one copy, even though there are two copies of each of these genes in each cell. What process or processes are responsible for this phenomenon?

Accepted Answer

A)  X-chromosome inactivation
B)  Mendelian inheritance
C)  combinatorial gene regulation
D)  epigenetic inheritance
E)  None of the answer options is correct.F) A) and B)
G) C) and D)

Question 4

Which one of the following describes an event that takes place during gene regulation at the level of the chromosome?

Accepted Answer

A)  Chromatin becomes condensed in order for transcription to begin.
B)  Chromatin coils so it can become more accessible to the proteins that carry out transcription.
C)  RNA polymerase and associated proteins bind to nucleosomes.
D)  Chromatin is remodeled and nucleosomes are repositioned so that specific regions of the DNA are made available for transcription.
E)  Cytosine bases in the sequence near the promoter of a gene become methylated in order to stimulate transcription.F) D) and E)
G) A) and E)

Question 5

The enzymatic processing of a polypeptide chain is an example of:

Accepted Answer

A)  signal transduction.
B)  post-transcriptional modification.
C)  dosage compensation.
D)  epigenetic modificationE) B) and C)
F) A) and C)

Question 6

In RNA editing:

Accepted Answer

A)  spliceosomes change the base sequence of the primary transcript and therefore the protein for which it codes.
B)  different spliceosomes in different cells create different RNA sequences from the same primary transcript.
C)  enzymes change the base sequence of the primary transcript and therefore the protein for which it codes.
D)  microRNAs in different cells create different primary RNA transcripts from the same DNA sequence.
E)  a combination of spliceosomes and enzymes creates different primary RNA transcripts from the same DNA sequence.F) C) and E)
G) B) and D)

Question 7

In the lactose operon of E. coli, the lacP- mutation:

Accepted Answer

A)  never produces the structural genes.
B)  produces the structural genes only in the presence of the inducer.
C)  produces the structural genes only in the absence of the inducer.
D)  produces the structural genes all the time.E) B) and C)
F) A) and D)

Question 8

Based on Figure 19.21, below, which of the following is NOT an accurate description of events leading to the lytic pathway following viral infection in a bacterium? L and PR. B) The transcripts from PR encode the proteins cro and cII. C) The cro protein represses transcription from PM so that the cl protein is not transcribed. D) Strong protease activity rapidly degrades cII, and cro continues to repress cI expression, leading to the lytic path. E) Reduced protease activity due to poor conditions allows cII to accumulate, which then stimulates transcription from PE and thus expression of cI." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Upon infection, transcription is initiated from promoters PL and PR.
B)  The transcripts from PR encode the proteins cro and cII.
C)  The cro protein represses transcription from PM so that the cl protein is not transcribed.
D)  Strong protease activity rapidly degrades cII, and cro continues to repress cI expression, leading to the lytic path.
E)  Reduced protease activity due to poor conditions allows cII to accumulate, which then stimulates transcription from PE and thus expression of cI.F) A) and E)
G) B) and D)

Question 9

In prokaryotes:

Accepted Answer

A)  the DNA is packaged into nucleosomes.
B)  the primary RNA transcript needs a "cap" at the 5' end for the initiation of translation.
C)  the translation of an mRNA can begin even before transcription is completed.
D)  translation of an mRNA cannot begin until transcription is completed.E) C) and D)
F) A) and B)

Question 10

In the type of RNA editing in which C is converted to U, which codons could be converted to a stop codon?

Accepted Answer

A)  ACG
B)  CAA
C)  ACC
D)  CAG
E)  CGAF) None of the above
G) A) and E)

Question 11

Insulin is needed to regulate sugar levels in the blood. While every cell in the body contains genes for the production of insulin, it is only produced by a specialized subset of cells in the pancreas. Therefore:

Accepted Answer

A)  every cell must regulate its own sugar production.
B)  the genes for insulin production must be mutated except in the specialized cells of the pancreas.
C)  there must be mechanisms of gene regulation that promote insulin expression in the specialized pancreatic cells and prevent insulin expression in all other cells.
D)  only the specialized cells of the pancreas have functional genes for insulin production.
E)  insulin production is not regulated because the genes for it are present in every cell.F) B) and E)
G) All of the above

Question 12

Gene regulation can occur through:

Accepted Answer

A)  DNA modification.
B)  histone modification.
C)  RNA modification.
D)  All of these choices are correct.E) A) and B)
F) B) and D)

Question 13

Which of the following statements about transcription in prokaryotes is INCORRECT?

Accepted Answer

A)  In prokaryotes, a transcriptional activator protein must bind the activator binding site prior to RNA polymerase complex binding at the promoter.
B)  In prokaryotes, the binding of a repressor protein to the repressor binding site prevents the binding of RNA polymerase complex.
C)  In prokaryotes, the RNA polymerase complex will bind to the promoter in the presence or absence of an activator protein and transcription will proceed.
D)  If an activator protein binds at a site far from the promoter sequence, transcription does not proceed efficiently.
E)  The binding sequence for an activator can be upstream of the promoter, downstream of the promoter, or overlapping with the promoter sequence.F) None of the above
G) D) and E)

Question 14

After small regulatory RNAs are transcribed and processed, specialized enzymes cleave the RNAs to double-stranded fragments that are typically around 20-25 nucleotides long.

Accepted Answer

A) True 
 B)False

Question 15

One type of RNA editing converts Cs to Us. In how many codons in the genetic code would such a change NOT affect what amino acid is translated?

Accepted Answer

A)  20
B)  22
C)  24
D)  25
E)  27F) B) and D)
G) C) and D)

Question 16

Adding or removing the 5' cap on messenger RNA helps regulate gene activity at the level of translation because the 5 cap is necessary for:

Accepted Answer

A)  RNA splicing.
B)  3 polyadenylation.
C)  translational initiation.
D)  translational termination.E) A) and B)
F) A) and C)

Question 17

In general, when cytosine bases in CpG islands are methylated:

Accepted Answer

A)  transcription is active and rapid.
B)  transcription is active, but slow.
C)  transcription is repressed.
D)  translation is active and rapid.
E)  translation is repressed.F) None of the above
G) All of the above

Question 18

A mutation is found that prevents transcription of the HOX3A gene, which is known to be in chromosome 12. Genetic mapping of the mutation suggests that it is located in chromosome 11. Which of the following could make these two observations possible?

Accepted Answer

A)  The mutation affects a transcription factor that binds to HOX3A gene sequences.
B)  The mutation changes the DNA sequence of an enhancer of the HOX3A gene.
C)  The mutation prevents ribosome binding by altering sequences of the HOX3A mRNA.
D)  The mutation increases transcription of an miRNA that has sequence homology to the HOX3A gene.E) C) and D)
F) None of the above

Question 19

Sometimes a prokaryotic activator protein interacts with a small molecule in the cell and undergoes a change in shape that alters its affinity for binding to DNA. This change in shape is an example of a(n)  _____ effect.

Accepted Answer

A)  allometric
B)  allosteric
C)  van der Waals
D)  isotonic
E)  hydrophobicF) C) and D)
G) A) and D)

Question 20

The methylation state of an individual CpG island:

Accepted Answer

A)  is fixed; such genes are permanently turned off.
B)  is fixed, but this has no effect on whether genes are expressed.
C)  is randomsometimes the cytosines are methylated and sometimes they're not, but the state is independent of the environment or cell type.
D)  can change over time in response to environmental cues, allowing genes to be turned on or off as needed.
E)  can change over time in response to environmental cues, but this has no effect on gene expression.F) A) and D)
G) B) and C)

Exam 19: Genetic and Epigenetic Regulation

In the lactose operon of E. coli, the lacP^- mutation:

Correct Answer
verified

Insulin is needed to regulate sugar levels in the blood. While every cell in the body contains genes for the production of insulin, it is only produced by a specialized subset of cells in the pancreas. Therefore:

Correct Answer
verified

Based on Figure 19.21, below, which of the following is NOT an accurate description of events leading to the lytic pathway following viral infection in a bacterium?

Correct Answer
verified

In the type of RNA editing in which C is converted to U, which codons could be converted to a stop codon?

Correct Answer
verified

The enzymatic processing of a polypeptide chain is an example of:

Correct Answer
verified

Which one of the following describes an event that takes place during gene regulation at the level of the chromosome?

Correct Answer
verified

The methylation state of an individual CpG island:

Correct Answer
verified

In general, when cytosine bases in CpG islands are methylated:

Correct Answer
verified

Correct Answer
verified

Adding or removing the 5' cap on messenger RNA helps regulate gene activity at the level of translation because the 5 cap is necessary for:

Correct Answer
verified

In RNA editing:

Correct Answer
verified

Sometimes a prokaryotic activator protein interacts with a small molecule in the cell and undergoes a change in shape that alters its affinity for binding to DNA. This change in shape is an example of a(n) _____ effect.

Correct Answer
verified

After small regulatory RNAs are transcribed and processed, specialized enzymes cleave the RNAs to double-stranded fragments that are typically around 20-25 nucleotides long.

Correct Answer
verified

Methylation is a mechanism often used by cells to prevent the expression of:

Correct Answer
verified

A mutation is found that prevents transcription of the HOX3A gene, which is known to be in chromosome 12. Genetic mapping of the mutation suggests that it is located in chromosome 11. Which of the following could make these two observations possible?

Correct Answer
verified

In prokaryotes:

Correct Answer
verified

Unlike processing of the primary transcript, RNA editing occurs at the level of mRNA.

Correct Answer
verified

Which of the following statements about transcription in prokaryotes is INCORRECT?

Correct Answer
verified

Gene regulation can occur through:

Correct Answer
verified

One type of RNA editing converts Cs to Us. In how many codons in the genetic code would such a change NOT affect what amino acid is translated?

Correct Answer
verified

Exam 19: Genetic and Epigenetic Regulation

In the lactose operon of E. coli, the lacP- mutation:

Correct AnswerverifiedShow Answer

Insulin is needed to regulate sugar levels in the blood. While every cell in the body contains genes for the production of insulin, it is only produced by a specialized subset of cells in the pancreas. Therefore:

Correct AnswerverifiedShow Answer

Based on Figure 19.21, below, which of the following is NOT an accurate description of events leading to the lytic pathway following viral infection in a bacterium?

Correct AnswerverifiedShow Answer

In the type of RNA editing in which C is converted to U, which codons could be converted to a stop codon?

Correct AnswerverifiedShow Answer

The enzymatic processing of a polypeptide chain is an example of:

Correct AnswerverifiedShow Answer

Which one of the following describes an event that takes place during gene regulation at the level of the chromosome?

Correct AnswerverifiedShow Answer

The methylation state of an individual CpG island:

Correct AnswerverifiedShow Answer

In general, when cytosine bases in CpG islands are methylated:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Adding or removing the 5' cap on messenger RNA helps regulate gene activity at the level of translation because the 5 cap is necessary for:

Correct AnswerverifiedShow Answer

In RNA editing:

Correct AnswerverifiedShow Answer

Sometimes a prokaryotic activator protein interacts with a small molecule in the cell and undergoes a change in shape that alters its affinity for binding to DNA. This change in shape is an example of a(n) _____ effect.

Correct AnswerverifiedShow Answer

After small regulatory RNAs are transcribed and processed, specialized enzymes cleave the RNAs to double-stranded fragments that are typically around 20-25 nucleotides long.

Correct AnswerverifiedShow Answer

Methylation is a mechanism often used by cells to prevent the expression of:

Correct AnswerverifiedShow Answer

A mutation is found that prevents transcription of the HOX3A gene, which is known to be in chromosome 12. Genetic mapping of the mutation suggests that it is located in chromosome 11. Which of the following could make these two observations possible?

Correct AnswerverifiedShow Answer

In prokaryotes:

Correct AnswerverifiedShow Answer

Unlike processing of the primary transcript, RNA editing occurs at the level of mRNA.

Correct AnswerverifiedShow Answer

Which of the following statements about transcription in prokaryotes is INCORRECT?

Correct AnswerverifiedShow Answer

Gene regulation can occur through:

Correct AnswerverifiedShow Answer

One type of RNA editing converts Cs to Us. In how many codons in the genetic code would such a change NOT affect what amino acid is translated?

Correct AnswerverifiedShow Answer

In the lactose operon of E. coli, the lacP^- mutation:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified