Deck 20: Parvoviruses

Question 1

Which of the following is NOT a function of the NS1 protein from minute virus of mice,an autonomous parvovirus?

A)Stimulates transcription from its own p4 promoter.
B)Stimulates transcription from the p38 promoter.
C)Unwinds DNA hairpins during genome replication.
D)Nicks viral DNA during genome replication.
E)Regulates splicing of the viral mRNAs.

Answer 1

E

Question 2

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

A)It is degraded.
B)It integrates into a nonspecific location on a human chromosome.
C)It integrates into a specific location on chromosome 19.
D)It is replicated,just more slowly in the absence of the helper virus.
E)It is maintained as an episome in the nucleus of the infected cell.

Answer 2

C

Question 3

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

A)It helps the parvovirus package new virions.
B)It helps the parvovirus enter the nucleus.
C)It induces the host cell to enter S phase.
D)It provides a DNA polymerase for genome replication.
E)It provides an RNA polymerase for gene expression.

Answer 3

C

Question 4

Which of the following is an advantage of the parvovirus AAV genome integrating into the human genome?

A)The viral genome is passed on to daughter cells.
B)The viral genome disrupts the gene for an antiviral protein.
C)The viral genome can be more easily transcribed by the cellular RNA polymerase.
D)The viral genome can never be excised to begin a productive infection.
E)The viral genome becomes stabilized by histones in the chromatin.

Question 5

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

A)Single-stranded DNA.
B)Double-stranded DNA.
C)Positive-sense single-stranded RNA.
D)Negative-sense single-stranded RNA.
E)Double-stranded RNA.

Question 6

Which of the following diseases is NOT caused by a parvovirus?

A)Panleukopenia
B)Aplastic crisis in anemia patients
C)Erythema infectiosum
D)Birth defects
E)Neurological problems.

Question 7

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

A)They do not have a double-stranded DNA genome.
B)They circularize their genome so that there are no ends.
C)They use a covalently bound protein as a primer.
D)They have self-complementary ends that serve as primers.
E)They encode a special DNA polymerase that can replicate ends of DNA.

Question 8

Which of the following steps has been shown to be blocked in cells that are nonpermissive for parvoviruses?

A)Binding of the virion to the correct receptor.
B)Uncoating of the virion.
C)Transcription of viral mRNAs.
D)Synthesis of viral proteins.
E)Replication of the viral genome.

Question 9

Parvoviruses can only productively infect cells that are NOT going through the cell cycle.

Question 10

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

A)That DNA polymerase does not require a pre-existing primer.
B)The removal of the primer from the 3' end of the new DNA strand.
C)The removal of the primer from the 5' end of the new DNA strand.
D)That the primer is composed of RNA rather than DNA.
E)That DNA polymerases can not synthesize DNA in the 5' to 3' direction.

Question 11

The Rep78 protein from the parvovirus adeno-associated virus has all of the following protein domains or enzymatic functions EXCEPT….

A)DNA binding domain.
B)Helicase domain.
C)Coiled-coil domain.
D)Actin binding domain.
E)Zinc finger domain.

Question 12

Which of the following describes the major difference between the gene expression strategies between different members of the parvovirus family?

A)Some use alternative mRNA splicing and some do not.
B)They use different numbers of transcriptional promoters.
C)Some use alternative start codons and some do not.
D)Some use RNA editing and some do not.

Question 13

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

A)Dependoviruses require the host cell DNA polymerase.
B)Dependoviruses require the host cell RNA polymerase.
C)Dependoviruses require coinfection with an adenovirus.
D)Dependoviruses are packaged in the virion of another virus.

Question 14

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

A)Tumor cells have a reduced interferon response than normal cells.
B)Tumor cells bind to more parvovirus virions than normal cells.
C)Tumor cells have reduced DNA damage response than normal cells.
D)Tumor cells go through the cell cycle more quickly than normal cells.
E)None of the above.

Question 15

Which of the following distinguishes the parvoviruses from adenoviruses and polyomaviruses?

A)They have naked capsids.
B)They replicate in the nucleus.
C)They require the cellular DNA polymerase.
D)They cannot induce the cell to enter S phase.
E)They have a DNA genome.

Question 16

Which of the following viral proteins is responsible for the integration of the genome of the parvovirus adeno-associate virus into the host chromosome?

A)Rep40
B)Rep78
C)VP1
D)VP2
E)integrase

Question 17

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

A)Self-complementary hairpin structures.
B)5' cap structures and 3' poly(A)tails.
C)5' triphosphate.
D)Covalently attached proteins.
E)The genome is circular so it has no ends.

Question 18

The dependoviruses,which are a group of parvoviruses,require coinfection with an adenovirus or herpesvirus to undergo a productive infection.

Question 19

Which of the following describes the first step in the replication cycle of the autonomous parvoviruses?

A)Translation of the incoming genome into proteins.
B)Transcription of the incoming genome into early mRNAs.
C)Synthesis of double-stranded DNA from the incoming genome.
D)Alterative splicing of the incoming genome.
E)Integration of the incoming genome into the host chromosome.

Question 20

Which of the following describes a major difference between how the genomes of autonomous parvoviruses and dependoviruses are packaged?

A)They both package either the positive or negative sense strand.
B)Autonomous parvoviruses package only the positive sense strand while dependoviruses package double-stranded DNA.
C)Autonomous parvoviruses package only the negative sense strand while dependoviruses package only the positive sense strand.
D)Autonomous parvoviruses package only the positive sense strand while dependoviruses package only the negative sense strand.
E)Autonomous parvoviruses package only the negative sense strand while dependoviruses package either the positive or negative sense strand.

Question 21

Explain why the ends of DNA can not be completely replicated and how the parvoviruses use the self-complementary ends to solve this problem.

Question 22

The oncotropism exhibited by parvoviruses means that they replicate more efficiently in tumor cells.

Question 23

The parvovirus genome must first be converted to double-stranded DNA before it can be transcribed into mRNAs.

Question 24

When researchers first isolated the DNA genomes from the virions of the adeno-assocaited virus,a member of the dependovirus group of parvoviruses,they thought they were double-stranded.Explain why and how they were able to determine the correct genome structure.

Question 25

The absence of the minor capsid proteins in parvovirus virions does not reduce infectivity.

Question 26

Eukaryotic cellular chromosomes use the same mechanism as the parvoviruses to maintain the ends of their linear DNA.