Question 1

Retroviral genomes tend to mutate at a very high rate. What statement BEST explains this observation?

Accepted Answer

A)   The RNA genome is highly susceptible to chemical damage.
B)   Specific enzymes in cells will modify the genome as a protection against infection.
C)   RNA phosphodiester bonds will tend to hydrolyze spontaneously.
D)   The virus changes the sequence to prevent antibody binding to the viral genome.
E)   Reverse transcriptase lacks a 3' to 5'exonuclease activity.F) A) and D)
G) A) and B)

Question 2

Which polymerase does NOT require a template?

Accepted Answer

A)   RNA Pol I
B)   RNA Pol II
C)   reverse transcriptase
D)   polyadenylate polymerase
E)   RNA replicaseF) A) and C)
G) B) and C)

Question 3

What is a telomere? Describe the key features of its structure. What is unusual about the structure and/or mechanism of action of telomerase?

Accepted Answer

A telomere is a region of repetitive nuc...

Question 4

Which eukaryotic transcription factor has helicase activity?

Accepted Answer

A)   TFIIA
B)   TFIIB
C)   TFIIF
D)   TFIIH
E)   TBPF) A) and E)
G) B) and C)

Question 5

Which compound is NOT a posttranscriptional modification in mRNA or tRNA?

Accepted Answer

A)   4-thiouridine
B)   pseudouridine
C)   dihydrouridine
D)   ribouridine
E)   ribothymidineF) B) and C)
G) A) and E)

Question 6

Write the sequence of the messenger RNA molecule synthesized from a DNA template strand having the sequence:
(5')ATCGTACCGTTA(3')

Accepted Answer

To write the sequence of the messenger R...

Question 7

Which statement is FALSE regarding transcription at RNA polymerase II promoters?

Accepted Answer

A)   Transcription requires binding of TBP to the -10 promoter element.
B)   TFIIB binds TBP and recruits TFIIF that directs RNA polymerase II to the promoter.
C)   TFIIH unwinds the DNA and phosphorylates the CTD of RNA polymerase II.
D)   TFIIH subunits contribute to a nucleotide-excision repair process.
E)   During the elongation phase, elongation factors suppress RNA polymerase II pausing and coordinate protein-protein interactions.F) B) and E)
G) A) and B)

Question 8

Compare and contrast $\rho$-dependent and $\rho$-independent termination of transcription in prokaryotes.

Accepted Answer

In prokaryotes, transcription terminatio...

Question 9

Which compound is NOT part of miRNA formation?

Accepted Answer

A)   pri-miRNA
B)   pre-miRNA
C)   Dicer
D)   RISC
E)   pseudouridineF) C) and E)
G) All of the above

Question 10

Describe in words (not using structures) the important features of the structures present on the 5' and 3' ends of mature (processed) eukaryotic mRNAs.

Accepted Answer

The 5' end of mature eukaryotic mRNAs co...

Question 11

Below, an RNA molecule is being transcribed from a strand of DNA. Indicate the 5' and 3' ends of the RNA molecule and of the strand of DNA that is complementary to the RNA molecule. In which direction is synthesis occurring?

Accepted Answer

The answer of Below, an RNA molecule is being transcribed...

Question 12

In the synthesis of the 5' cap of mRNA, what enzyme classes are used at each step?

Accepted Answer

The synthesis of the 5' cap structure of...

Question 13

What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase   δ\deltaδ  ?

Accepted Answer

A)   Both enzymes require nucleic acid templates.
B)   Both enzymes include proof-reading functions.
C)   Both enzymes use dNTPs as substrates for synthesis.
D)   Both enzymes require metal cofactors.
E)   All of the statements are true. F) A) and C)
G) C) and D)

Question 14

In eukaryotic splicing, U1-snRNP:

Accepted Answer

A)   is made entirely of RNA.
B)   is a component of the active splicesosome.
C)   is complementary to the 5' splice site for the intron.
D)   becomes covalently attached to a lariat intermediate.
E)   dissociates from the spliceosomal complex after lariat formation.F) A) and B)
G) D) and E)

Question 15

The sigma factor of E. coli RNA polymerase:

Accepted Answer

A)   associates with the promoter before binding core enzyme.
B)   combines with the core enzyme to confer specific binding to a promoter.
C)   is inseparable from the core enzyme.
D)   is required for termination of an RNA chain.
E)   will catalyze synthesis of RNA from both DNA template strands in the absence of the core enzyme.F) A) and E)
G) D) and E)

Question 16

AZT is one drug used as an HIV inhibitor. How does it specifically inhibit viral replication?

Accepted Answer

A)   AZT is not taken up by human cells.
B)   AZT binds to human polymerases with lower affinity than to viral reverse transcriptase.
C)   AZT cannot be phosphorylated to a triphosphate.
D)   AZT only inhibits active transcription and not DNA replication.
E)   AZT inhibits viral assembly and packing.F) A) and E)
G) All of the above

Question 17

Which statement is FALSE with respect to different  σ\sigmaσ  (sigma)  subunits in bacterial RNA polymerase?

Accepted Answer

A)   Specific amino acids in  σ\sigmaσ  subunits will interact with the polymerase.
B)    σ\sigmaσ  subunits will specifically interact with DNA sequences spanning approximately three turns of the helix.
C)    σ\sigmaσ  subunits interact with both DNA and the RNA polymerase in the elongation form.
D)   Multiple  σ\sigmaσ  subunits exist in E. coli.
E)   The binding of NusA is competitive with the binding of  σ\sigmaσ  subunits in E. coli. F) C) and D)
G) A) and E)

Question 18

RNA polymerase:

Accepted Answer

A)   binds tightly to a region of DNA thousands of base pairs away from the DNA to be transcribed.
B)   can synthesize RNA chains without a primer.
C)   has a subunit called  λ\lambdaλ  (lambda) , which acts as a proofreading ribonuclease.
D)   separates DNA strands throughout a long region of DNA (up to thousands of base pairs) , then copies one of them.
E)   synthesizes RNA chains in the 3'  →\rightarrow→  5' direction. F) A) and E)
G) None of the above

Question 19

Which process is involved in generating the different forms of the apoB gene product in liver and intestines?

Accepted Answer

A)   alternative 5' splice-site choice
B)   alternative 3' splice-site choice
C)   a C  →\rightarrow→  U deamination
D)   All of these processes are involved.
E)   None of these processes is involved. F) B) and E)
G) A) and E)

Question 20

Processing of a primary mRNA transcript in a eukaryotic cell does NOT normally involve:

Accepted Answer

A)   attachment of a long poly(
A)   sequence at the 3' end.
B)   conversion of normal bases to modified bases, such as inosine and pseudouridine.
C)   excision of intervening sequences (introns) .
D)   joining of exons.
E)   methylation of one or more guanine nucleotides at the 5' end.F) B) and E)
G) C) and E)

Exam 26: RNA Metabolism

Which polymerase does NOT require a template?

Correct AnswerverifiedShow Answer

In the synthesis of the 5' cap of mRNA, what enzyme classes are used at each step?

Correct AnswerAnswered by ExamLex AIThe synthesis of the 5' cap structure of...View AnswerShow Answer

Below, an RNA molecule is being transcribed from a strand of DNA. Indicate the 5' and 3' ends of the RNA molecule and of the strand of DNA that is complementary to the RNA molecule. In which direction is synthesis occurring?

Correct AnswerverifiedShow Answer

AZT is one drug used as an HIV inhibitor. How does it specifically inhibit viral replication?

Correct AnswerverifiedShow Answer

What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase δ\deltaδ ?

Correct AnswerverifiedShow Answer

Which statement is FALSE regarding transcription at RNA polymerase II promoters?

Correct AnswerverifiedShow Answer

In eukaryotic splicing, U1-snRNP:

Correct AnswerverifiedShow Answer

Which compound is NOT part of miRNA formation?

Correct AnswerverifiedShow Answer

The sigma factor of E. coli RNA polymerase:

Correct AnswerverifiedShow Answer

Processing of a primary mRNA transcript in a eukaryotic cell does NOT normally involve:

Correct AnswerverifiedShow Answer

RNA polymerase:

Correct AnswerverifiedShow Answer

What is a telomere? Describe the key features of its structure. What is unusual about the structure and/or mechanism of action of telomerase?

Correct AnswerAnswered by ExamLex AIA telomere is a region of repetitive nuc...View AnswerShow Answer

Which statement is FALSE with respect to different σ\sigmaσ (sigma) subunits in bacterial RNA polymerase?

Correct AnswerverifiedShow Answer

Which eukaryotic transcription factor has helicase activity?

Correct AnswerverifiedShow Answer

Retroviral genomes tend to mutate at a very high rate. What statement BEST explains this observation?

Correct AnswerverifiedShow Answer

Which compound is NOT a posttranscriptional modification in mRNA or tRNA?

Correct AnswerverifiedShow Answer

Which process is involved in generating the different forms of the apoB gene product in liver and intestines?

Correct AnswerverifiedShow Answer

Compare and contrast ρ\rhoρ -dependent and ρ\rhoρ -independent termination of transcription in prokaryotes.

Correct AnswerAnswered by ExamLex AIIn prokaryotes, transcription terminatio...View AnswerShow Answer

Write the sequence of the messenger RNA molecule synthesized from a DNA template strand having the sequence: (5')ATCGTACCGTTA(3')

Correct AnswerAnswered by ExamLex AITo write the sequence of the messenger R...View AnswerShow Answer

Describe in words (not using structures) the important features of the structures present on the 5' and 3' ends of mature (processed) eukaryotic mRNAs.

Correct AnswerAnswered by ExamLex AIThe 5' end of mature eukaryotic mRNAs co...View AnswerShow Answer

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The synthesis of the 5' cap structure of...
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What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase $\delta$ ?

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A telomere is a region of repetitive nuc...
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Which statement is FALSE with respect to different $\sigma$ (sigma) subunits in bacterial RNA polymerase?

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Compare and contrast $\rho$ -dependent and $\rho$ -independent termination of transcription in prokaryotes.

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Answered by ExamLex AI
In prokaryotes, transcription terminatio...
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Answered by ExamLex AI
To write the sequence of the messenger R...
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Correct Answer
Answered by ExamLex AI
The 5' end of mature eukaryotic mRNAs co...
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