Question 1

Which of the following enzymes are never encoded by viral genes?

Accepted Answer

A)  RNA replicase.
B)  Reverse transcriptase.
C)  RNA polymerase I.
D)  Proteases.
E)  Integrase.F) A) and B)
G) C) and D)

Question 2

Azidothymidine (AZT; also called zidovudine)  is a structural analog of thymidine.On the basis of its structure, what is its most likely mode of action against the human immunodeficiency virus (HIV) ?

Accepted Answer

A)  It is a protease inhibitor (inhibits gag-pol processing) .
B)  It is an integrase inhibitor.
C)  It causes early termination of HIV cDNA synthesis.
D)  It causes early termination of HIV RNA synthesis.
E)  It blocks the translation of viral proteins.F) C) and E)
G) B) and C) C

Question 3

The long terminal repeats of the acquired immunodeficiency syndrome (AIDS)  virus are recognized by integrase and help direct the incorporation of viral complementary DNA (cDNA)  into the genome.What else are they good for?

Accepted Answer

A)  They encode the matrix and core proteins.
B)  They form the primer for reverse transcriptase.
C)  They encode reverse transcriptase.
D)  They encode the proteins required to process gag-pol.
E)  They contain the viral promoter region.F) A) and E)
G) A) and D) E

Question 4

Unlike bacteriophage T₄, l phage is capable of both lytic and lysogenic infection.The lysogenic state is maintained by:

Accepted Answer

A)  Chemical modification of cytosine bases in the viral DNA, forming hydroxymethyl-cytosine.
B)  Transcription of the cro gene.
C)  Transcription of the gene for the l repressor.
D)  Transcription of the xis and cro genes.
E)  Exposure of the bacterium to ultraviolet radiation or other DNA-damaging agents.F) A) and E)
G) A) and D) C

Exam 10: Viruses

Which of the following enzymes are never encoded by viral genes?

Correct Answer
verified

Azidothymidine (AZT; also called zidovudine) is a structural analog of thymidine.On the basis of its structure, what is its most likely mode of action against the human immunodeficiency virus (HIV) ?

Correct Answer
verified
C

The long terminal repeats of the acquired immunodeficiency syndrome (AIDS) virus are recognized by integrase and help direct the incorporation of viral complementary DNA (cDNA) into the genome.What else are they good for?

Correct Answer
verified
E

Unlike bacteriophage T₄, l phage is capable of both lytic and lysogenic infection.The lysogenic state is maintained by:

Correct Answer
verified
C

Exam 10: Viruses

Which of the following enzymes are never encoded by viral genes?

Correct AnswerverifiedShow Answer

Azidothymidine (AZT; also called zidovudine) is a structural analog of thymidine.On the basis of its structure, what is its most likely mode of action against the human immunodeficiency virus (HIV) ?

Correct AnswerverifiedC

The long terminal repeats of the acquired immunodeficiency syndrome (AIDS) virus are recognized by integrase and help direct the incorporation of viral complementary DNA (cDNA) into the genome.What else are they good for?

Correct AnswerverifiedE

Unlike bacteriophage T₄, l phage is capable of both lytic and lysogenic infection.The lysogenic state is maintained by:

Correct AnswerverifiedC

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified
E

Correct Answer
verified
C