Lecture 5 and 6 quiz

Question 1

Which of the following describes the type of nucleic acid used in the genomes of parvoviruses?

Single-stranded DNA

Positive-sense single-stranded RNA

Double-stranded DNA

Double-stranded RNA

Negative-sense single-stranded RNA

Answer 1

Single-stranded DNA

Question 2

Which of the following distinguishes the parvoviruses from the polyomaviruses?

They have a DNA genome

They replicate in the nucleus

They cannot induce the cell to enter S phase

They require the cellular DNA polymerase

They have naked capsids

Answer 2

They cannot induce the cell to enter S phase

Question 3

Which of the following distinguishes the dependoviruses from the autonomous parvoviruses?

Dependoviruses require the host cell RNA polymerase

Dependoviruses replicate in the cell nucleus

Dependoviruses require the host cell DNA polymerase

Dependoviruses do not have an envelope

Dependoviruses require coinfection with an adenovirus

Answer 3

Dependoviruses require coinfection with an adenovirus

Question 4

Which of the following describes the structures found at the ends of the parvovirus genomes?

Covalently attached proteins

The genome is circular so it has no ends

5’ triphosphate

Self-complementary hairpin structures

5’ cap structures and 3’ poly(A) tails

Answer 4

Self-complementary hairpin structures

Question 5

What major function does coinfection with an adenovirus provide to adeno-associated virus, a member of the dependovirus group of parvoviruses?

It helps the parvovirus enter the nucleus

It provides an RNA polymerase for gene expression

It provides a DNA polymerase for genome replication

It helps the parvovirus package new virions

It induces the host cell to enter S phase

Answer 5

It induces the host cell to enter S phase

Question 6

How do parvoviruses solve the problem of replicating the ends of linear DNA molecules?

They circularize their genome so that there are no ends

They encode a special DNA polymerase that can replicate ends of DNA

They do not have a double-stranded DNA genome

They have self-complementary ends that serve as primers

They use a covalently bound protein as a primer

Answer 6

They have self-complementary ends that serve as primers

Question 7

Which of the following describes the fate of the AAV parvovirus genome in the absence of a helper virus?

It is replicated, just more slowly in the absence of the helper virus

It is degraded

It is maintained as an episome in the nucleus of the infected cell

It integrates into a nonspecific location on a human chromosome

It integrates into a specific location on chromosome 19

Answer 7

It integrates into a specific location on chromosome 19

Question 8

The problem with replicating the ends of linear DNA is due to which of the following?

That DNA polymerase does not require a pre-existing primer

That the primer is composed of RNA rather than DNA.

The removal of the primer from the 3’ end of the new DNA strand

That DNA polymerases can not synthesize DNA in the 5’ to 3’ direction.

The removal of the primer from the 5’ end of the new DNA strand

Answer 8

The removal of the primer from the 5’ end of the new DNA strand

Question 9

Which of the following does NOT explain why parvoviruses replicate better in tumor cells than in normal cells?

Question 9 options:

Tumor cells have a reduced interferon response than normal cells

Tumor cells bind to more parvovirus virions than normal cells

Tumor cells go through the cell cycle more quickly than normal cells.

Tumor cells have reduced DNA damage response than normal cells

None of the answers.

Answer 9

Tumor cells bind to more parvovirus virions than normal cells

Question 10

The simian virus 40 (SV40) was isolated from which of the following?

Cells used to produce poliovirus vaccine

Monkeys used for HIV research

Hepatitis virus B vaccine

Mouse tissue extracts

Human adenoidal tissue

Answer 10

Cells used to produce poliovirus vaccine

Question 11

Under which of the following conditions do polyomaviruses cause tumors in their hosts?

Injection of high titers in older animals

None will produce tumors

Exposure to the virus via an aerosol

Exposure to particularly tumorigenic strains of the virus

Injection of high titers in young animals

Answer 11

Injection of high titers in young animals

Question 12

Which of the following describes the structure of the polyomavirus capsid?

72 capsomeres composed of hexamers of VP1

72 capsomeres composed of pentamers of VP1

60 capsomeres composed of hexamers of VP1

60 capsomeres composed of pentamers of VP1

12 capsomeres composed of pentamers of VP1 with the remaining capsomeres composed of hexamers of VP1

Answer 12

72 capsomeres composed of pentamers of VP1

Question 13

Which of the following cellular proteins are packaged into the polyomavirus virions?

Tubulin monomers

Histone octomers

Actin monomers

Myristylated proteins

Transcription factors

Answer 13

Histone octomers

Question 14

If the histone proteins are removed from genome of SV40, which of the following will happen?

The DNA assumes a relaxed circle form

The DNA becomes supercoiled

The DNA becomes denatured

Nothing happens to the DNA

The DNA becomes nicked

Answer 14

The DNA becomes supercoiled

Question 15

Which of the following mechanisms is used by SV40 to produce several proteins from a single transcription unit?

Use of alternative start codons

Alternative mRNA splicing

All of the mechanisms are used

RNA editing

Ribosomal frameshifting

Answer 15

Alternative mRNA splicing

Question 16

The large T antigen from SV40 can bind to all of the following cellular proteins EXCEPT….

p300

pRb

Poly(A) polymerase

DNA polymerase a

p53

Answer 16

Poly(A) polymerase

Question 17

SV40 induces the infected cell to enter the S phase of the cell cycle. What purpose does this serve for the virus?

The virus requires transcription factors made during S phase

The virus requires the DNA replication enzymes made during S phase

The virus requires the breakdown of the nuclear envelope

The virus requires the cellular splicing enzymes present during S phase

The virus requires the RNA polymerase II only present during S phase

Answer 17

The virus requires the DNA replication enzymes made during S phase

Question 18

Binding of the large T antigen of SV40 to the cellular protein pRb causes which of the following to occur?

Disassociation of the transcription factor E2F

Blocks progression through the cell cycle

Degradation of the cellular protein p53

Activation of the apoptosis pathway

Replication of viral DNA

Answer 18

Disassociation of the transcription factor E2F

Question 19

Which of the following must occur in nonpermissive cells which become transformed by the polyomavirus SV40?

The viral origin of replication must become inactivated

Cellular DNA becomes packaged into virions

The large T antigen proteins become degraded

The Rb protein becomes bound to E2F

The early viral genes become integrated into the host chromosome

Answer 19

The early viral genes become integrated into the host chromosome

Question 20

The small T antigen of SV40 regulates the cell cycle of the host cell by DIRECTLY doing which of the following?

Inactivating the p53 protein

Inhibiting the activity of the PP2A phosphatase

Turning on the activity of the MAP kinase

Turning on transcription of cyclin D1

Phosphorylating the transcription factor AP1

Answer 20

Inhibiting the activity of the PP2A phosphatase