Question 1

The protein projections on the surface of a virus that are involved in attachment to the host cell are called

Accepted Answer

A)  suckers. 
B)  pili. 
C)  cilia. 
D)  spikes. 
E)  hooks. 
A)  suckers. 
B)  pili. 
C)  cilia. 
D)  spikes. 
E)  hooks.

Question 2

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. 
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.

Question 3

When an enveloped virus adsorbs to the host cell with its protein spikes, the virions are taken into the cell by the process of

Accepted Answer

A)  penetration. 
B)  production. 
C)  fusion. 
D)  endocytosis. 
A)  penetration. 
B)  production. 
C)  fusion. 
D)  endocytosis.

Question 4

Diseases of short duration frequently followed by long-term immunity are referred to as

Accepted Answer

A)  intermittent infections. 
B)  chronic infections. 
C)  acute infections. 
D)  persistent infections. 
A)  intermittent infections. 
B)  chronic infections. 
C)  acute infections. 
D)  persistent infections.

Question 5

There are _______ families of RNA containing viruses that infect vertebrates.

Accepted Answer

A)  two 
B)  five 
C)  seven 
D)  fourteen 
A)  two 
B)  five 
C)  seven 
D)  fourteen

Question 6

The protein coat of a virus

Accepted Answer

A)  is called a capsomere. 
B)  is called a capsid. 
C)  protects the nucleic acid. 
D)  is involved in recognition of host cell receptors. 
E)  is called a capsid, protects the nucleic acid AND is involved in recognition of host cell receptors. 
A)  is called a capsomere. 
B)  is called a capsid. 
C)  protects the nucleic acid. 
D)  is involved in recognition of host cell receptors. 
E)  is called a capsid, protects the nucleic acid AND is involved in recognition of host cell receptors.

Question 7

If a virus utilizes a lytic life cycle of reproduction, it will not induce tumors.

Accepted Answer

A) True 
 B)False

Question 8

Virulent as well as temperate phages can serve as generalized transducing phages.

Accepted Answer

A) True 
 B)False

Question 9

The correct order for the stages of a phage infection is:

Accepted Answer

A)  penetration, transcription, attachment, replication of nucleic acid and protein, assembly, release 
B)  attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release 
C)  attachment, replication of nucleic acid and protein, penetration, transcription, assembly, release 
D)  transcription, attachment replication of nucleic acid and protein, assembly, penetration, release 
A)  penetration, transcription, attachment, replication of nucleic acid and protein, assembly, release 
B)  attachment, penetration, transcription, replication of nucleic acid and protein, assembly, release 
C)  attachment, replication of nucleic acid and protein, penetration, transcription, assembly, release 
D)  transcription, attachment replication of nucleic acid and protein, assembly, penetration, release

Question 10

Phage-encoded proteins are

Accepted Answer

A)  coded for by host DNA. 
B)  coded for by phage DNA. 
C)  proteins normally present in the uninfected cell. 
D)  early proteins. 
E)  coded for by phage DNA AND early proteins. 
A)  coded for by host DNA. 
B)  coded for by phage DNA. 
C)  proteins normally present in the uninfected cell. 
D)  early proteins. 
E)  coded for by phage DNA AND early proteins.

Question 11

All viruses must separate the nucleic acid from the capsid before replication.

Accepted Answer

A) True 
 B)False

Question 12

You add an unknown phage to a mixture of F+ and F- cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F-. How can you explain this phenomenon?

Accepted Answer

A)  The phage bound to a receptor on the sex pilus, and therefore only infected the F+ cells (leaving the F- cells alone). 
B)  The phage bound to a receptor on the F- cells, leaving only them alive and allowing the F+ cells to die off. 
C)  The phage integrated (lysogenized) the F- cells, giving them a selective advantage over the F+ cells. 
D)  F+ cells are uniquely susceptible to phage attack for unknown reasons. 
A)  The phage bound to a receptor on the sex pilus, and therefore only infected the F+ cells (leaving the F- cells alone). 
B)  The phage bound to a receptor on the F- cells, leaving only them alive and allowing the F+ cells to die off. 
C)  The phage integrated (lysogenized) the F- cells, giving them a selective advantage over the F+ cells. 
D)  F+ cells are uniquely susceptible to phage attack for unknown reasons.

Question 13

The term filterable viruses was coined by

Accepted Answer

A)  Beijerinck. 
B)  Iwanowsky. 
C)  Twort. 
D)  d'Herelle. 
A)  Beijerinck. 
B)  Iwanowsky. 
C)  Twort. 
D)  d'Herelle.

Question 14

Bacteria infected with filamentous phages are termed

Accepted Answer

A)  temperate cells. 
B)  plaque-producing cells. 
C)  virulent strains. 
D)  carrier cells. 
A)  temperate cells. 
B)  plaque-producing cells. 
C)  virulent strains. 
D)  carrier cells.

Question 15

Filamentous virus is incapable of causing a lytic infection.

Accepted Answer

A) True 
 B)False

Question 16

The approximate viral concentration of a sample may be determined by

Accepted Answer

A)  quantal assay. 
B)  endpoint assay. 
C)  the titer. 
D)  the lysate assay. 
A)  quantal assay. 
B)  endpoint assay. 
C)  the titer. 
D)  the lysate assay.

Question 17

One group of animal viruses that are able to agglutinate red blood cells are the

Accepted Answer

A)  coronavirus. 
B)  retrovirus. 
C)  reovirus. 
D)  myxovirus. 
A)  coronavirus. 
B)  retrovirus. 
C)  reovirus. 
D)  myxovirus.

Question 18

The integration of phage DNA into host DNA occurs in much the same fashion as seen in transformation, transduction or conjugation.

Accepted Answer

A) True 
 B)False

Question 19

What is a defective phage?

Accepted Answer

A)  A virus that has lost some of its genetic material, and therefore cannot infect a new target cell. 
B)  A virus that has lost some of its genetic material, and therefore cannot replicate within a new target cell. 
C)  A virus that lacks the ability to replicate independently of its host cell. 
D)  A virus that cannot attach to its host cell. 
A)  A virus that has lost some of its genetic material, and therefore cannot infect a new target cell. 
B)  A virus that has lost some of its genetic material, and therefore cannot replicate within a new target cell. 
C)  A virus that lacks the ability to replicate independently of its host cell. 
D)  A virus that cannot attach to its host cell.

Question 20

A limiting factor for viral infection is

Accepted Answer

A)  internal metabolic temperature of the host cell. 
B)  nutrition of the host cell. 
C)  stage of cell cycle of the host cell. 
D)  presence of specific receptor molecules on the host cell. 
A)  internal metabolic temperature of the host cell. 
B)  nutrition of the host cell. 
C)  stage of cell cycle of the host cell. 
D)  presence of specific receptor molecules on the host cell.

Exam 13: Viruses, Viroids and Prions

The protein projections on the surface of a virus that are involved in attachment to the host cell are called

Transducing virulent phages do not lyse the cells they invade because

When an enveloped virus adsorbs to the host cell with its protein spikes, the virions are taken into the cell by the process of

Diseases of short duration frequently followed by long-term immunity are referred to as

There are _______ families of RNA containing viruses that infect vertebrates.

The protein coat of a virus

If a virus utilizes a lytic life cycle of reproduction, it will not induce tumors.

Virulent as well as temperate phages can serve as generalized transducing phages.

The correct order for the stages of a phage infection is:

Phage-encoded proteins are

All viruses must separate the nucleic acid from the capsid before replication.

You add an unknown phage to a mixture of F+ and F- cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F-. How can you explain this phenomenon?

The term filterable viruses was coined by

Bacteria infected with filamentous phages are termed

Filamentous virus is incapable of causing a lytic infection.

The approximate viral concentration of a sample may be determined by

One group of animal viruses that are able to agglutinate red blood cells are the

The integration of phage DNA into host DNA occurs in much the same fashion as seen in transformation, transduction or conjugation.

What is a defective phage?

A limiting factor for viral infection is

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Prokaryotic Growth

Control of Microbial Growth

Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology and Recombinant Dna

Identification and Classification of Prokaryotes

The Diversity of Prokaryotic Organisms

The Eukaryotic Members of the Microbial World

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunologic Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Genitourinary Infections

Nervous System Infections

Blood and Lymphatic Infections

Hiv Disease and Complications of Immunodeficiency

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

Filters

You add an unknown phage to a mixture of F⁺ and F^- cells of E. coli and plate out the bacteria. The bacterial colonies that grow are all F^-. How can you explain this phenomenon?