Question 1

Which of the following best describes leucine zipper motifs?

Accepted Answer

A)   They allow protein-protein interactions via hydrophobic bonds.
B)   They allow protein-protein interactions via hydrogen bonds.
C)   They allow protein-protein interactions via electrostatic interactions.
D)   They allow protein-DNA interactions by fitting into the major groove of DNA.

Question 2

At what point does the sigma ( σ )  subunit of RNA polymerase released from the core enzyme?

Accepted Answer

A)   Prior to the incorporation of any nucleotides into an RNA strand.
B)   After transcription begins and about 10 nucleotides have been added to the RNA chain.
C)   Just prior to chain termination.
D)   Never; it is an intrinsic part of the core enzyme.
E)   After RNA polymerase discovers an inverted repeat

Question 3

A commonly encountered feature of transfer RNA synthesis is

Accepted Answer

A)   the precursor of several tRNA molecules is transcribed in one long polynucleotide sequence
B)   there is little or no base modification after transcription
C)   modification of the sugar moiety never takes place
D)   the covalent binding of tRNA to specific proteins

Question 4

Which of the following is not true?

Accepted Answer

A)   The mechanism of activation of eukaryotic genes involves addition and removal of phosphate residues from some of the transcription factors.
B)   In plants, there are 5 RNA polymerases.
C)   RNA Pol IV is the primary RNA synthesizer in plants
D)   Of the RNA Polymerases in eukaryotes, Pol II is the most extensively studied.

Question 5

TATA-binding protein (TBP)  is normally required for transcription by

Accepted Answer

A)   Pol I.
B)   Pol II.
C)   Pol III.
D)   all of these polymerases.
E)   none of these polymerases D

Question 6

The promoter site is

Accepted Answer

A)   the start site for transcription in DNA
B)   the binding site for regulatory proteins that stimulate transcription
C)   the general region of DNA downstream from the start site
D)   the site on DNA at which RNA polymerase binds to initiate transcription
E)   None of these

Question 7

Ribozymes, the catalytic activity of RNA, were first discovered as part of the snRNA group.

Accepted Answer

A) True 
 B)False

Question 8

Which of following statements describes a difference between replication of DNA and transcription of RNA?

Accepted Answer

A)   Nucleoside triphosphates are the precursors for replication, but nucleoside diphosphates are used for transcription.
B)   Both strands of DNA are copied in replication, but usually only one is copied in transcription.
C)   Base pairing is used to copy the sequence in replication, but not in transcription.
D)   The chain grows from the 5' to the 3' end in replication, but 3' to 5' in transcription.
E)   None of these B

Question 9

Which of following statements concerning RNA transcription is false ?

Accepted Answer

A)   The release of pyrophosphate from a nucleoside triphosphate drives the reaction.
B)   RNA is synthesized from the 5' end to the 3' end.
C)   DNA to RNA base pairing includes A to U and G to C.
D)   Transcription requires the use of a primer.
E)   None of these

Question 10

A mutation in the lac A gene would result in

Accepted Answer

A)   continuous production of the proteins encoded by the three structural genes
B)   continuous production of the lac repressor
C)   normal operation of the lac operon, but with an alteration in the proteins encoded by the lac A gene
D)   no transcription from the lac operon

Question 11

A single operon

Accepted Answer

A)   usually contains all the enzymes which are specific for the synthesis of a special biomolecule.
B)   usually does not contain all the enzymes which are specific for the synthesis of a special biomolecule.
C)   usually contains only a single structural gene for a critical enzyme.
D)   usually contains only a gene for a repressor.

Question 12

Which of the following best describes the order of events at the promoter?

Accepted Answer

A)   open complex → closed complex → transcription initiation
B)   closed complex → open complex → transcription initiation
C)   open complex → transcription initiation → closed complex
D)   transcription initiation → open complex → closed complex

Question 13

​ Identify the component  of the prokaryotic promoter that is 40 to 60 bases subsequent to the transcription start site and that enhances the binding of RNA polymerase.

Accepted Answer

A)   Core promoter
B)   −35 element
C)   UP element
D)   Pribnow box

Question 14

Which of the following transcription factors is involved in the elongation phase of eukaryotic transcription?

Accepted Answer

A)   TFIIA
B)   TFIID
C)   TFIIF
D)   There are no transcription factors associated with elongation.

Question 15

Transcription in eukaryotes differs from RNA synthesis in prokaryotes

Accepted Answer

A)   by requiring a primer.
B)   by simplifying the process with multifunctional enzymes.
C)   in using more complex σ factors.
D)   by having multiple RNA polymerases rather than one. D

Question 16

Which of the following is not a structural motif encountered in DNA-binding proteins?

Accepted Answer

A)   helix-turn-helix
B)   leucine zipper
C)   zinc finger
D)   β− barrel

Question 17

Which of the following is the best description of an operon?

Accepted Answer

A)   An enhancer that positively regulates gene expression.
B)   An silencer that negatively regulates gene expression.
C)   A binding element for the sigma ( σ )  factor.
D)   A group of genes under the control of a common promoter.

Question 18

Which of the following is more often associated with transcription being switched off?

Accepted Answer

A)   Presence of histone remodeling complexes SWI\SNF
B)   Active Histone Acetyltransferase
C)   Unmethylated cytosines
D)   Methylated cytosines
E)   None of these

Question 19

Which of the following is not true about RISC?

Accepted Answer

A)   It is only involved in cleaving dsRNA from viruses
B)   It is involved with processing of miRNA and siRNA
C)   It uses a protein from the argonaut family
D)   It unwinds dsRNA and eventually discards the passenger strand

Question 20

The combination of events revolving around chromatin remodeling that controls transcription is known as:

Accepted Answer

A)   The genetic code
B)   The second genetic code
C)   The histone code
D)   Histone deacetylase code
E)   None of these

Exam 11: Transcription of the Genetic Code the Biosynthesis of Rna

Which of the following best describes leucine zipper motifs?

Correct AnswerverifiedShow Answer

At what point does the sigma ( σ ) subunit of RNA polymerase released from the core enzyme?

Correct AnswerverifiedShow Answer

A commonly encountered feature of transfer RNA synthesis is

Correct AnswerverifiedShow Answer

Which of the following is not true?

Correct AnswerverifiedShow Answer

TATA-binding protein (TBP) is normally required for transcription by

Correct AnswerverifiedD

The promoter site is

Correct AnswerverifiedShow Answer

Ribozymes, the catalytic activity of RNA, were first discovered as part of the snRNA group.

Correct AnswerverifiedShow Answer

Which of following statements describes a difference between replication of DNA and transcription of RNA?

Correct AnswerverifiedB

Which of following statements concerning RNA transcription is false ?

Correct AnswerverifiedShow Answer

A mutation in the lac A gene would result in

Correct AnswerverifiedShow Answer

A single operon

Correct AnswerverifiedShow Answer

Which of the following best describes the order of events at the promoter?

Correct AnswerverifiedShow Answer

​ Identify the component of the prokaryotic promoter that is 40 to 60 bases subsequent to the transcription start site and that enhances the binding of RNA polymerase.

Correct AnswerverifiedShow Answer

Which of the following transcription factors is involved in the elongation phase of eukaryotic transcription?

Correct AnswerverifiedShow Answer

Transcription in eukaryotes differs from RNA synthesis in prokaryotes

Correct AnswerverifiedD

Which of the following is not a structural motif encountered in DNA-binding proteins?

Correct AnswerverifiedShow Answer

Which of the following is the best description of an operon?

Correct AnswerverifiedShow Answer

Which of the following is more often associated with transcription being switched off?

Correct AnswerverifiedShow Answer

Which of the following is not true about RISC?

Correct AnswerverifiedShow Answer

The combination of events revolving around chromatin remodeling that controls transcription is known as:

Correct AnswerverifiedShow Answer

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D

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B

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Identify the component of the prokaryotic promoter that is 40 to 60 bases subsequent to the transcription start site and that enhances the binding of RNA polymerase.

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D

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