Question 1

Glycoprotein spikes protruding from the outer surface of viral envelopes function as

Accepted Answer

A)   toxins.
B)   factors that bind to host cells.
C)   cell lysis factors.
D)   factors needed for site specific recombination.E) A) and C)
F) B) and D)

Question 2

Animal viruses have been cultivated in

Accepted Answer

A)   suitable host animals.
B)   embryonated eggs.
C)   tissue cultures (monolayers of animal cells) .
D)   all of the choicesE) C) and D)
F) A) and B)

Question 3

Viruses that are polyhedrons with 20 sides are said to have __________ symmetry.

Accepted Answer

The answer of Viruses that are polyhedrons with 20 sides...

Question 4

A ________ assay is most useful for determining the viability of a viral preparation?

Accepted Answer

A)   direct (electron microscopic)  count
B)   hemagglutination
C)   plaque
D)   PCRE) All of the above
F) B) and D)

Question 5

Bacterial viruses are so named because they have prokaryotic cell structures similar to their bacterial hosts.

Accepted Answer

A) True 
 B)False

Question 6

Viral envelopes are composed of

Accepted Answer

A)   proteins.
B)   lipids.
C)   carbohydrates.
D)   all of the choicesE) A) and B)
F) A) and C)

Question 7

Which of the following can be used to cultivate plant viruses?

Accepted Answer

A)   cultures of separated plant cells
B)   whole plants
C)   plant protoplast cultures
D)   All of these can be used to cultivate plant viruses.E) A) and C)
F) B) and D)

Question 8

The largest of the viruses are similar in size to some small bacteria and are large enough to be seen with a light microscope.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is/are not true about viral envelopes?

Accepted Answer

A)   The envelope proteins are virus specific.
B)   The envelope lipids and carbohydrates are derived from the host.
C)   They are typical lipid monolayers with embedded viral proteins.
D)   The envelope proteins are virus specific and the envelope lipids and carbohydrates are derived from the hostE) B) and C)
F) B) and D)

Question 10

Viruses in the extracellular state possess few, if any, active enzymes.

Accepted Answer

A) True 
 B)False

Question 11

A __________ genome exists as several separate, nonidentical molecules that may be packaged together or separately.

Accepted Answer

A)   diploid
B)   segmented
C)   polyploid
D)   fractionatedE) C) and D)
F) B) and C)

Question 12

In which of the following stages of the viral infectious cycle do enveloped viruses usually acquire their envelopes?

Accepted Answer

A)   penetration
B)   component biosynthesis
C)   assembly
D)   releaseE) None of the above
F) A) and B)

Question 13

Human cancer causing viruses most often have a ___________ genome.

Accepted Answer

A)   ssDNA
B)   dsDNA
C)   ssRNA
D)   dsRNAE) A) and D)
F) A) and C)

Question 14

The presence or absence of an envelope is not useful in classifying viruses because any given virus may at one time have an envelope and at another time not have an envelope.

Accepted Answer

A) True 
 B)False

Question 15

Viral capsid protein subunits are called

Accepted Answer

A)   auxomers.
B)   elastomers.
C)   protomers.
D)   viromers.E) C) and D)
F) All of the above

Question 16

Many of the enzymes found in virus particles are

Accepted Answer

A)   required for viral attachment to host cells.
B)   involved in viral entry into host cells.
C)   involved in the replication of viral nucleic acid.
D)   all of the choicesE) None of the above
F) A) and B)

Question 17

The mechanism of pathogenesis by prions may involve a conformational change in the prion protein (PrP) to an abnormal form.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following is true of viruses in the extracellular phase?

Accepted Answer

A)   They possess many different enzymes.
B)   They can reproduce independently of living cells but only at a slow rate.
C)   They behave as a macromolecular complex and are no more alive than are ribosomes.
D)   They possess many different enzymes and they can reproduce independently of living cells but only at a slow rateE) B) and C)
F) A) and B)

Question 19

Genes whose expression (or abnormal expression)  causes cancer are called

Accepted Answer

A)   cancer genes.
B)   progenies.
C)   oncogenes.
D)   carcinogens.E) A) and B)
F) None of the above

Question 20

Available evidence is consistent with the proposal that prion diseases are caused by infectious proteins.

Accepted Answer

A) True 
 B)False

Exam 5: Viruses and Other Acellular Infectious Agents

The largest of the viruses are similar in size to some small bacteria and are large enough to be seen with a light microscope.

Correct AnswerverifiedShow Answer

Which of the following is true of viruses in the extracellular phase?

Correct AnswerverifiedShow Answer

Available evidence is consistent with the proposal that prion diseases are caused by infectious proteins.

Correct AnswerverifiedShow Answer

Viruses that are polyhedrons with 20 sides are said to have __________ symmetry.

Correct AnswerverifiedShow Answer

In which of the following stages of the viral infectious cycle do enveloped viruses usually acquire their envelopes?

Correct AnswerverifiedShow Answer

A __________ genome exists as several separate, nonidentical molecules that may be packaged together or separately.

Correct AnswerverifiedShow Answer

The presence or absence of an envelope is not useful in classifying viruses because any given virus may at one time have an envelope and at another time not have an envelope.

Correct AnswerverifiedShow Answer

Which of the following can be used to cultivate plant viruses?

Correct AnswerverifiedShow Answer

Bacterial viruses are so named because they have prokaryotic cell structures similar to their bacterial hosts.

Correct AnswerverifiedShow Answer

Which of the following is/are not true about viral envelopes?

Correct AnswerverifiedShow Answer

Viruses in the extracellular state possess few, if any, active enzymes.

Correct AnswerverifiedShow Answer

The mechanism of pathogenesis by prions may involve a conformational change in the prion protein (PrP) to an abnormal form.

Correct AnswerverifiedShow Answer

Viral envelopes are composed of

Correct AnswerverifiedShow Answer

A ________ assay is most useful for determining the viability of a viral preparation?

Correct AnswerverifiedShow Answer

Glycoprotein spikes protruding from the outer surface of viral envelopes function as

Correct AnswerverifiedShow Answer

Many of the enzymes found in virus particles are

Correct AnswerverifiedShow Answer

Animal viruses have been cultivated in

Correct AnswerverifiedShow Answer

Viral capsid protein subunits are called

Correct AnswerverifiedShow Answer

Human cancer causing viruses most often have a ___________ genome.

Correct AnswerverifiedShow Answer

Genes whose expression (or abnormal expression) causes cancer are called

Correct AnswerverifiedShow Answer

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