Question 1

The discovery of retroviruses changed our understanding of

Accepted Answer

A)  gene structure and organization. 
B)  the flow of genetic information. 
C)  protein synthesis. 
D)  infectious particles. 
A)  gene structure and organization. 
B)  the flow of genetic information. 
C)  protein synthesis. 
D)  infectious particles.

Question 2

Which of the following are the hosts for most enveloped viruses?

Accepted Answer

A)  Bacteria 
B)  animals 
C)  Archaea 
D)  fungi 
A)  Bacteria 
B)  animals 
C)  Archaea 
D)  fungi

Question 3

A virus that kills its host is said to be

Accepted Answer

A)  lytic or virulent. 
B)  temperate. 
C)  lysogenic. 
D)  virulent or lysogenic, but not temperate. 
A)  lytic or virulent. 
B)  temperate. 
C)  lysogenic. 
D)  virulent or lysogenic, but not temperate.

Question 4

When solutions of host cells and infectious virions are mixed and spread on an agar plate,________ form where viruses lyse the host cells.

Accepted Answer

A)  insertion sequences 
B)  plaques 
C)  prophages 
D)  colonies 
A)  insertion sequences 
B)  plaques 
C)  prophages 
D)  colonies

Question 5

Based on your knowledge of cellular and viral processes,which of the following would be (an)appropriate target(s)for antiviral drugs?

Accepted Answer

A)  integrases 
B)  aminoacyl-tRNA synthetases 
C)  ribosomes 
D)  aminoacyl-tRNA synthetases and ribosomes 
A)  integrases 
B)  aminoacyl-tRNA synthetases 
C)  ribosomes 
D)  aminoacyl-tRNA synthetases and ribosomes

Question 6

T4 genes are transcribed by host RNA polymerase,yet the transcription of T4 genes is carefully controlled so that groups of T4 genes are transcribed at specific times after infection.How is this accomplished?

Accepted Answer

A)  Early T4 genes encode for proteolytic enzymes that destroy the host RNA polymerase. Subsequently a viral polymerase is created that transcribes the middle and late genes in the correct order. 
B)  Early and middle T4 genes encode for proteins that modify the activity of sigma factors and host RNA polymerase to regulate the expression of T4 genes. 
C)  Each group of T4 genes has a different promoter that indicates that order in which they should be transcribed in based on the affinity of the promoter for the host RNA polymerase. 
D)  Rolling circle replication of the viral genome ensures that the genes are available for transcription in the correct order. 
A)  Early T4 genes encode for proteolytic enzymes that destroy the host RNA polymerase. Subsequently a viral polymerase is created that transcribes the middle and late genes in the correct order. 
B)  Early and middle T4 genes encode for proteins that modify the activity of sigma factors and host RNA polymerase to regulate the expression of T4 genes. 
C)  Each group of T4 genes has a different promoter that indicates that order in which they should be transcribed in based on the affinity of the promoter for the host RNA polymerase. 
D)  Rolling circle replication of the viral genome ensures that the genes are available for transcription in the correct order.

Question 7

A lytic infection results in death of the host cell.

Accepted Answer

A) True 
 B)False

Question 8

Virions infecting some bacteria possess the enzyme ________ that makes a small hole in the bacterial cell wall,allowing the viral nucleic acid to enter.

Accepted Answer

A)  peptidoglycanase 
B)  infectase 
C)  lysozyme 
D)  nuclease 
A)  peptidoglycanase 
B)  infectase 
C)  lysozyme 
D)  nuclease

Question 9

An RNA genome itself serves as mRNA in negative-stranded RNA viruses.

Accepted Answer

A) True 
 B)False

Question 10

ALL viral particles

Accepted Answer

A)  are metabolically inert. 
B)  are smaller than bacterial cells. 
C)  contain an envelope to prevent its degradation outside of a host. 
D)  exhibit cell lysis under a particular condition. 
A)  are metabolically inert. 
B)  are smaller than bacterial cells. 
C)  contain an envelope to prevent its degradation outside of a host. 
D)  exhibit cell lysis under a particular condition.

Question 11

Explain the relationship between the terms virus particle,virion,and virus genome.

Accepted Answer

A virus particle is a broad term used to

Question 12

Whether lambda phage undergoes the lytic or lysogenic cycle is dependent on the accumulation of

Accepted Answer

A)  Cro protein. 
B)  viral genomes. 
C)  cI protein. 
D)  methylated DNA. 
A)  Cro protein. 
B)  viral genomes. 
C)  cI protein. 
D)  methylated DNA.

Question 13

Viral proteins are categorized as early,middle,and late.Early proteins typically are necessary for

Accepted Answer

A)  production of viral mRNA. 
B)  packaging of DNA into the nucleocapsid. 
C)  copying the viral genome. 
D)  production of viral mRNA and copying the viral genome. 
A)  production of viral mRNA. 
B)  packaging of DNA into the nucleocapsid. 
C)  copying the viral genome. 
D)  production of viral mRNA and copying the viral genome.

Question 14

Although T4 encodes over 250 proteins,it does not encode its own RNA polymerase.

Accepted Answer

A) True 
 B)False

Question 15

Some viruses possess icosahedral heads and helical tails.

Accepted Answer

A) True 
 B)False

Question 16

The packaging mechanism of T4 DNA involves cutting of DNA from

Accepted Answer

A)  linear genetic elements. 
B)  circular genetic elements. 
C)  DNA concatemers. 
D)  its host cells. 
A)  linear genetic elements. 
B)  circular genetic elements. 
C)  DNA concatemers. 
D)  its host cells.

Question 17

Why was the discovery of retroviruses important to the field of molecular biology?

Accepted Answer

The discovery of retroviruses was import

Question 18

There is at least one known virus whose genome is actually larger than a cellular genome.

Accepted Answer

A) True 
 B)False

Question 19

What genome composition makes viruses most susceptible to destruction by prokaryotic restriction endonucleases?

Accepted Answer

A)  dsDNA 
B)  ssDNA 
C)  dsRNA 
D)  ssRNA 
A)  dsDNA 
B)  ssDNA 
C)  dsRNA 
D)  ssRNA

Question 20

The primer for retrovirus reverse transcription is a specific

Accepted Answer

A)  tRNA encoded by the cell. 
B)  tRNA encoded by the virus. 
C)  nuclear tRNA. 
D)  nuclear tDNA. 
A)  tRNA encoded by the cell. 
B)  tRNA encoded by the virus. 
C)  nuclear tRNA. 
D)  nuclear tDNA.

Exam 8: Viruses and Virology

The discovery of retroviruses changed our understanding of

Which of the following are the hosts for most enveloped viruses?

A virus that kills its host is said to be

When solutions of host cells and infectious virions are mixed and spread on an agar plate,________ form where viruses lyse the host cells.

Based on your knowledge of cellular and viral processes,which of the following would be (an)appropriate target(s)for antiviral drugs?

T4 genes are transcribed by host RNA polymerase,yet the transcription of T4 genes is carefully controlled so that groups of T4 genes are transcribed at specific times after infection.How is this accomplished?

A lytic infection results in death of the host cell.

Virions infecting some bacteria possess the enzyme ________ that makes a small hole in the bacterial cell wall,allowing the viral nucleic acid to enter.

An RNA genome itself serves as mRNA in negative-stranded RNA viruses.

ALL viral particles

Explain the relationship between the terms virus particle,virion,and virus genome.

Whether lambda phage undergoes the lytic or lysogenic cycle is dependent on the accumulation of

Viral proteins are categorized as early,middle,and late.Early proteins typically are necessary for

Although T4 encodes over 250 proteins,it does not encode its own RNA polymerase.

Some viruses possess icosahedral heads and helical tails.

The packaging mechanism of T4 DNA involves cutting of DNA from

Why was the discovery of retroviruses important to the field of molecular biology?

There is at least one known virus whose genome is actually larger than a cellular genome.

What genome composition makes viruses most susceptible to destruction by prokaryotic restriction endonucleases?

The primer for retrovirus reverse transcription is a specific

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