Question 1

Once inside the host cell, phage DNA

Accepted Answer

A)  is replicated.
B)  is transcribed.
C)  may get degraded by bacterial nucleases.
D)  All of the choices are correct. D

Question 2

Bacteriophages and animal viruses

Accepted Answer

A)  both may enter a host cell by endocytosis.
B)  both may enter a host cell by fusion.
C)  both involve entry of the entire nucleocapsid.
D)  differ because bacteriophages leave the capsid outside the cell, while animal virus entry involves the entry of the whole nucleocapsid. D

Question 3

Once integrated, phage DNA can remain in the prophage state as long as

Accepted Answer

A)  the bacteria is frequently plated on new media.
B)  certain phage genes are excised.
C)  certain phage genes are repressed.
D)  bacterial repressor genes are activated. C

Question 4

The changes that occur in virally-infected cells are characteristic for a particular virus and are referred to as the

Accepted Answer

A)  cytopathic effect.
B)  phenotypic effect.
C)  genotypic expression.
D)  cytology.

Question 5

Transduction often involves defective virus.

Accepted Answer

A) True 
 B)False

Question 6

Enveloped viruses

Accepted Answer

A)  just require a stamp.
B)  have an outer lipid bilayer membrane containing various proteins.
C)  are surrounded by an additional layer of carbohydrate.
D)  envelope a cell.

Question 7

In addition to lysis, animal viruses may exit the host cell by

Accepted Answer

A)  extrusion.
B)  budding.
C)  fission.
D)  fusion.

Question 8

A phage that replicates inside the host cell and then lyses its host during its release is a

Accepted Answer

A)  virulent or lytic phage.
B)  latent phage.
C)  lysogenic phage.
D)  dormant phage.

Question 9

The replicative form of nucleic acid in filamentous phages is

Accepted Answer

A)  dsDNA.
B)  dsRNA.
C)  positive ssRNA.
D)  negative ssDNA.

Question 10

In the region of budding, the inside of the plasma membrane becomes coated with

Accepted Answer

A)  enzymes.
B)  carbohydrates.
C)  steroids.
D)  matrix proteins.

Question 11

Retroviruses are unique in that they

Accepted Answer

A)  replicate in nervous system cells.
B)  do not have a capsid.
C)  use RNA as a template to make DNA.
D)  use DNA as a template to make RNA.

Question 12

Which is a filamentous phage?

Accepted Answer

A)  M13
B)  T4
C)  lambda
D)  phi X174

Question 13

The term "segmented" refers to viruses that

Accepted Answer

A)  may contain several pieces of RNA.
B)  have an icosahedral-shaped capsid.
C)  are linked together before budding out.
D)  have an envelope.

Question 14

A temperate phage

Accepted Answer

A)  may be lysogenic.
B)  may be lytic.
C)  enters a lysogenic or lytic life cycle shortly after entering the host cell.
D)  are all RNA viruses.
E)  may be lysogenic AND enters a lysogenic or lytic life cycle shortly after entering the host cell.

Question 15

Assembly of the T4 phage

Accepted Answer

A)  may involve some self-assembly.
B)  may involve the use of scaffolds.
C)  is completely self-assembly.
D)  is completely dependent on scaffolds.
E)  may involve some self-assembly AND may involve the use of scaffolds.

Question 16

After growth in tissue culture, the infected cells lyse and the virus may be harvested from

Accepted Answer

A)  the liquid supernatant after centrifugation, the lysate.
B)  the remainder.
C)  the quantal layer.
D)  the monolayer.

Question 17

The restriction-modification system always has two genes involved, the cutting enzyme and the methylating enzyme.

Accepted Answer

A) True 
 B)False

Question 18

Prions are

Accepted Answer

A)  a form of RNA virus.
B)  a form of DNA virus.
C)  a viroid.
D)  an infectious protein.

Question 19

Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA are called

Accepted Answer

A)  lysogenic phages.
B)  lytic phages.
C)  virulent phages.
D)  segmented phages.

Question 20

Transducing virulent phages do not lyse the cells they invade because

Accepted Answer

A)  transformation is taking place in the phage and this is transferred to the bacterium.
B)  bacterial DNA has replaced critical viral DNA in the phage.
C)  their virulence is dependent on the bacteria and virus replicating together.
D)  the lytic genes are unable to enter during penetration and are shed outside the host.

Exam 13: Viruses, Viroids and Prions

Once inside the host cell, phage DNA

Bacteriophages and animal viruses

Once integrated, phage DNA can remain in the prophage state as long as

The changes that occur in virally-infected cells are characteristic for a particular virus and are referred to as the

Transduction often involves defective virus.

Enveloped viruses

In addition to lysis, animal viruses may exit the host cell by

A phage that replicates inside the host cell and then lyses its host during its release is a

The replicative form of nucleic acid in filamentous phages is

In the region of budding, the inside of the plasma membrane becomes coated with

Retroviruses are unique in that they

Which is a filamentous phage?

The term "segmented" refers to viruses that

A temperate phage

Assembly of the T4 phage

After growth in tissue culture, the infected cells lyse and the virus may be harvested from

The restriction-modification system always has two genes involved, the cutting enzyme and the methylating enzyme.

Prions are

Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA are called

Transducing virulent phages do not lyse the cells they invade because