Question 1

Which of the following statements is true of the enzyme Pol II?

Accepted Answer

A)  The phosphorylated form of the enzyme is necessary for initiating transcription. 
B)  The unphosphorylated form of the enzyme is necessary for the elongation of mRNA. 
C)  The unphosphorylated form of the enzyme is necessary for the termination of transcription. 
D)  The phosphorylated form of the enzyme is necessary for the elongation of mRNA. 
A)  The phosphorylated form of the enzyme is necessary for initiating transcription. 
B)  The unphosphorylated form of the enzyme is necessary for the elongation of mRNA. 
C)  The unphosphorylated form of the enzyme is necessary for the termination of transcription. 
D)  The phosphorylated form of the enzyme is necessary for the elongation of mRNA.

Question 2

Which of the following statements is true of the structural sequence of a gene?

Accepted Answer

A)  It is made of exons and introns. 
B)  It is made of promoters and enhancers. 
C)  It controls the function of regulatory genes. 
D)  It controls the expression of initiation factors. 
A)  It is made of exons and introns. 
B)  It is made of promoters and enhancers. 
C)  It controls the function of regulatory genes. 
D)  It controls the expression of initiation factors.

Question 3

Which of the following control elements inhibit transcription?

Accepted Answer

A)  enhancers 
B)  promoters 
C)  silencers 
D)  operators 
A)  enhancers 
B)  promoters 
C)  silencers 
D)  operators

Question 4

Which statement is true of the translocation phase of elongation during protein synthesis?

Accepted Answer

A)  The empty tRNA moves to the A site of the ribosomal complex. 
B)  The empty tRNA moves to the T site of the ribosomal complex. 
C)  The dipeptide moves from the A site to the P site of the ribosomal complex. 
D)  The dipeptide moves from the P site to the A site of the ribosomal complex. 
A)  The empty tRNA moves to the A site of the ribosomal complex. 
B)  The empty tRNA moves to the T site of the ribosomal complex. 
C)  The dipeptide moves from the A site to the P site of the ribosomal complex. 
D)  The dipeptide moves from the P site to the A site of the ribosomal complex.

Question 5

Which of the following ensures proper alignment of the small ribosomal unit on the mRNA during protein synthesis?

Accepted Answer

A)  the anticodon 
B)  the codon 
C)  the Shine-Dalgarno sequence 
D)  the initiation sequence 
A)  the anticodon 
B)  the codon 
C)  the Shine-Dalgarno sequence 
D)  the initiation sequence

Question 6

Which of the following statements is true of DNA methylation?

Accepted Answer

A)  It usually silences the expression of a gene. 
B)  It usually increases the expression of a gene. 
C)  It usually deletes the promoter sequence of DNA. 
D)  It usually adds extra nucleotides to a sequence of DNA. 
A)  It usually silences the expression of a gene. 
B)  It usually increases the expression of a gene. 
C)  It usually deletes the promoter sequence of DNA. 
D)  It usually adds extra nucleotides to a sequence of DNA.

Question 7

Which of the following is a function of an aminoacyl-tRNA synthetase?

Accepted Answer

A)  It catalyzes the binding of the smaller ribosomal subunit to its specific tRNA. 
B)  It catalyzes the binding of the larger ribosomal subunit to its specific tRNA. 
C)  It catalyzes the binding of a specific amino acid to its specific tRNA. 
D)  It catalyzes the binding of a specific transcription factor to its specific tRNA. 
A)  It catalyzes the binding of the smaller ribosomal subunit to its specific tRNA. 
B)  It catalyzes the binding of the larger ribosomal subunit to its specific tRNA. 
C)  It catalyzes the binding of a specific amino acid to its specific tRNA. 
D)  It catalyzes the binding of a specific transcription factor to its specific tRNA.

Question 8

Which of the following is a function of a restriction endonuclease?

Accepted Answer

A)  It cleaves a DNA molecule at a specific site. 
B)  It cleaves a DNA molecule at random locations. 
C)  It removes specific codons from an mRNA molecule. 
D)  It removes specific exons from an mRNA molecule. 
A)  It cleaves a DNA molecule at a specific site. 
B)  It cleaves a DNA molecule at random locations. 
C)  It removes specific codons from an mRNA molecule. 
D)  It removes specific exons from an mRNA molecule.

Question 9

Which of the following is not involved in the regulation of transcription in eukaryotes?

Accepted Answer

A)  enhancers 
B)  promoters 
C)  response elements 
D)  tRNAs 
A)  enhancers 
B)  promoters 
C)  response elements 
D)  tRNAs

Question 10

Which of the following statements is true of enhancers?

Accepted Answer

A)  They are located next to the TATA box. 
B)  They are a part of the initiation sequence. 
C)  They increase the transcription of a gene above the basal level. 
D)  They contain bases that polymerases recognize as initial signals. 
A)  They are located next to the TATA box. 
B)  They are a part of the initiation sequence. 
C)  They increase the transcription of a gene above the basal level. 
D)  They contain bases that polymerases recognize as initial signals.

Question 11

The following generalized reaction is used in one of the techniques for synthesizing recombinant DNA. In this reaction, a double-stranded DNA sequence is cleaved at a specific site.   Which of the following enzymes is used in this reaction?

Accepted Answer

A)  DNA ligase 
B)  restriction endonuclease 
C)  peptidyl transferase 
D)  DNA synthetase 
A)  DNA ligase 
B)  restriction endonuclease 
C)  peptidyl transferase 
D)  DNA synthetase

Question 12

Examine the following diagram.   Which of the following numbers in the diagram represents a polymerase?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 13

Which of the following enzymes joins the two sticky ends of DNA?

Accepted Answer

A)  DNA ligase 
B)  restriction endonuclease 
C)  peptidyl transferase 
D)  adenosine deaminase 
A)  DNA ligase 
B)  restriction endonuclease 
C)  peptidyl transferase 
D)  adenosine deaminase

Question 14

Which of the following vectors is commonly used in ex vivo gene therapy?

Accepted Answer

A)  the adenovirus 
B)  the Maloney murine leukemia virus 
C)  the weakened flu virus 
D)  the vaccinia virus 
A)  the adenovirus 
B)  the Maloney murine leukemia virus 
C)  the weakened flu virus 
D)  the vaccinia virus

Question 15

Which of the following statements is true of chaperones?

Accepted Answer

A)  They are enhancers that help in cell signaling by responding to external stimuli. 
B)  They are methyl proteins that methylate amino acids in a DNA sequence. 
C)  They are DNA sequences that bind to transcription factors to slow the rate of transcription. 
D)  They are proteins that help in the proper folding of newly synthesized polypeptide chains. 
A)  They are enhancers that help in cell signaling by responding to external stimuli. 
B)  They are methyl proteins that methylate amino acids in a DNA sequence. 
C)  They are DNA sequences that bind to transcription factors to slow the rate of transcription. 
D)  They are proteins that help in the proper folding of newly synthesized polypeptide chains.

Question 16

How many stop codons are there?

Accepted Answer

A)  1 
B)  3 
C)  4 
D)  20 
A)  1 
B)  3 
C)  4 
D)  20

Question 17

Which of the following is a tumor suppressor protein?

Accepted Answer

A)  MDR1 
B)  p53 
C)  CFTR 
D)  ADA 
A)  MDR1 
B)  p53 
C)  CFTR 
D)  ADA

Question 18

Which of the following enzymes accelerate transcription based on external cell signals?

Accepted Answer

A)  phosphorylated protein kinases 
B)  helicases 
C)  tRNA synthetases 
D)  all of these 
A)  phosphorylated protein kinases 
B)  helicases 
C)  tRNA synthetases 
D)  all of these

Question 19

How many polymerases catalyze transcription in eukaryotes?

Accepted Answer

A)  one 
B)  two 
C)  three 
D)  four 
A)  one 
B)  two 
C)  three 
D)  four

Question 20

Which of the following statements is true of mRNA synthesis?

Accepted Answer

A)  mRNA is synthesized in the 3' → 5' direction and the polymerase moves along the DNA template in the 3' → 5' direction. 
B)  mRNA is synthesized in the 5' → 3' direction and the polymerase moves along the DNA template in the 5' → 3' direction. 
C)  mRNA is synthesized in the 3' → 5' direction, but the polymerase moves along the DNA template in the 5' → 3'direction. 
D)  mRNA is synthesized in the 5' → 3' direction, but the polymerase moves along the DNA template in the 3' → 5' direction. 
A)  mRNA is synthesized in the 3' → 5' direction and the polymerase moves along the DNA template in the 3' → 5' direction. 
B)  mRNA is synthesized in the 5' → 3' direction and the polymerase moves along the DNA template in the 5' → 3' direction. 
C)  mRNA is synthesized in the 3' → 5' direction, but the polymerase moves along the DNA template in the 5' → 3'direction. 
D)  mRNA is synthesized in the 5' → 3' direction, but the polymerase moves along the DNA template in the 3' → 5' direction.

Exam 25: Gene Expression and Protein Synthesis

Which of the following statements is true of the enzyme Pol II?

Which of the following statements is true of the structural sequence of a gene?

Which of the following control elements inhibit transcription?

Which statement is true of the translocation phase of elongation during protein synthesis?

Which of the following ensures proper alignment of the small ribosomal unit on the mRNA during protein synthesis?

Which of the following statements is true of DNA methylation?

Which of the following is a function of an aminoacyl-tRNA synthetase?

Which of the following is a function of a restriction endonuclease?

Which of the following is not involved in the regulation of transcription in eukaryotes?

Which of the following statements is true of enhancers?

The following generalized reaction is used in one of the techniques for synthesizing recombinant DNA. In this reaction, a double-stranded DNA sequence is cleaved at a specific site. Which of the following enzymes is used in this reaction?

Examine the following diagram. Which of the following numbers in the diagram represents a polymerase?

Which of the following enzymes joins the two sticky ends of DNA?

Which of the following vectors is commonly used in ex vivo gene therapy?

Which of the following statements is true of chaperones?

How many stop codons are there?

Which of the following is a tumor suppressor protein?

Which of the following enzymes accelerate transcription based on external cell signals?

How many polymerases catalyze transcription in eukaryotes?

Which of the following statements is true of mRNA synthesis?

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