Question 1

Why is it virtually impossible to eradicate a disease caused by a zoonotic virus?

Accepted Answer

A)   You would have to drive the vector organism extinct to do so.
B)   Many vector organisms have multiple stages of their life cycle that can carry a zoonotic virus, which complicates controlling the vector-borne transmission.
C)   Many viruses transmitted in this manner may utilize more than one vector organism.
D)   Many zoonotic viruses may be able to reside in more than one host organism, complicating control measures.
E)   All of the answer choices are correct.

Question 2

Attachment of animal viruses to the host cell may be by means of

Accepted Answer

A)   a tail.
B)   the envelope.
C)   spikes.
D)   a capsid.
E)   a membrane.

Question 3

The genome of retroviruses is made of

Accepted Answer

A)   ssDNA.
B)   dsDNA.
C)   ssRNA.
D)   dsRNA.
E)   protein and RNA.

Question 4

Why is it not surprising that AIDS patients frequently suffer a viral-induced tumor?

Accepted Answer

A)   HIV genomes integrate into the host cell chromosome. This integration might result in loss of control of the cell cycle (also known as cancer) .
B)   The immune system's CD4+ T cells are directly responsible for elimination of tumor cells. HIV attacks them and eliminates them, making a person more susceptible to cancer.
C)   The therapies for HIV are highly mutagenic, which may lead to cancerous states in people taking the drug regimen.
D)   Products of an active HIV infection are highly mutagenic; as a person's illness progresses, these compounds build up and induce a cancerous state.
E)   The DNA polymerases of people with AIDS lose any proofreading ability, so any mistakes that happen during DNA replication automatically lead to development of cancer.

Question 5

Retroviruses are unique in that they

Accepted Answer

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

Question 6

Animal viruses are divided into a number of families whose names end in

Accepted Answer

A)   -virus.
B)   -viridae.
C)   -viscous.
D)   -eieio.
E)   -virum.

Question 7

Prions affect the

Accepted Answer

A)   respiratory system.
B)   gastrointestinal tract.
C)   nervous system.
D)   lymphatic system.
E)   urogenital system.

Question 8

Normal tissue taken from animals and prepared immediately as a medium for viral growth is termed a(n)

Accepted Answer

A)   advantageous group.
B)   monolayer culture.
C)   primary culture.
D)   plaque.
E)   virus culture.

Question 9

The activation of the SOS system in a bacterium infected with a prophage results in

Accepted Answer

A)   destruction of certain bacterial genes AND destruction of the viral repressor through host protease activity.
B)   destruction of the viral repressor through host protease activity AND complete lysis of the bacterial culture.
C)   destruction of the viral repressor through host protease activity AND mutation of the DNA
D)   complete lysis of the bacterial culture, destruction of the viral genes, AND mutation of the DNA.
E)   destruction of certain bacterial genes AND complete lysis of the bacterial culture.

Question 10

There are ________ major families of RNA containing viruses that infect vertebrates.

Accepted Answer

A)   2
B)   5
C)   7
D)   13
E)   6

Question 11

The site at which a virus has infected and subsequently lysed the infected cell, releasing its progeny to infect and lyse surrounding cells, thereby forming a "clear zone," is

Accepted Answer

A)   a burst area.
B)   a lyse area.
C)   a plaque.
D)   a dead zone.
E)   a zone of inhibition.

Question 12

Capsids are made of a number of capsomeres that are covalently bonded to one another.

Accepted Answer

A) True 
 B)False

Question 13

Assembly of the T4 phage

Accepted Answer

A)   is completely self-assembly
B)   is completely dependent on scaffolds.
C)   may involve some self-assembly AND may involve the use of scaffolds.
D)   may involve some self-assembly AND is completely dependent on scaffolds.
E)   is completely self-assembly AND is never dependent on scaffolds.

Question 14

A lysogenic cell contains viral DNA (a prophage) integrated into the host chromosome.

Accepted Answer

A) True 
 B)False

Question 15

A virion is a(n)

Accepted Answer

A)   pathogenic virus.
B)   subviral particle.
C)   complete, extracellular virus particle.
D)   enveloped virus particle.
E)   non-enveloped virus particle.

Question 16

The terms helical, icosahedral, and complex refer to

Accepted Answer

A)   viral life cycles.
B)   forms of nucleic acid.
C)   types of viral envelopes.
D)   shapes of viruses.
E)   types of bacteriophages.

Question 17

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.

Question 18

What are two ways that phage can replicate without directly lysing their host cell?

Accepted Answer

A)   Conjugation and lysogeny
B)   Lysogeny and transduction
C)   Extrusion and transformation
D)   Extrusion and lysogeny
E)   Extrusion and lysis

Question 19

Using phages to treat a bacterial infection is an interesting idea because

Accepted Answer

A)   a single type of phage can destroy a wide range of strains of the same pathogen.
B)   of the increasing problem of antibiotic resistance in pathogens.
C)   lysed bacteria pose no threat to a person's health.
D)   a single phage can be genetically engineered to infect many different species of bacteria.
E)   of the increasing problem of antibiotic resistance in people.

Question 20

What part of the attached bacteriophage enters through the host cell wall?

Accepted Answer

A)   The entire virus.
B)   Only the enzymes necessary for replication.
C)   The nucleic acid.
D)   The nucleic acid and capsid.
E)   The capsid only.

Exam 13: Viruses, Viroids, and Prions

Using phages to treat a bacterial infection is an interesting idea because

Correct AnswerverifiedShow Answer

Retroviruses are unique in that they

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The activation of the SOS system in a bacterium infected with a prophage results in

Correct AnswerverifiedShow Answer

Why is it not surprising that AIDS patients frequently suffer a viral-induced tumor?

Correct AnswerverifiedShow Answer

Why is it virtually impossible to eradicate a disease caused by a zoonotic virus?

Correct AnswerverifiedShow Answer

Attachment of animal viruses to the host cell may be by means of

Correct AnswerverifiedShow Answer

The genome of retroviruses is made of

Correct AnswerverifiedShow Answer

What part of the attached bacteriophage enters through the host cell wall?

Correct AnswerverifiedShow Answer

A lysogenic cell contains viral DNA (a prophage) integrated into the host chromosome.

Correct AnswerverifiedShow Answer

Assembly of the T4 phage

Correct AnswerverifiedShow Answer

The site at which a virus has infected and subsequently lysed the infected cell, releasing its progeny to infect and lyse surrounding cells, thereby forming a "clear zone," is

Correct AnswerverifiedShow Answer

Animal viruses are divided into a number of families whose names end in

Correct AnswerverifiedShow Answer

There are ________ major families of RNA containing viruses that infect vertebrates.

Correct AnswerverifiedShow Answer

Capsids are made of a number of capsomeres that are covalently bonded to one another.

Correct AnswerverifiedShow Answer

What are two ways that phage can replicate without directly lysing their host cell?

Correct AnswerverifiedShow Answer

Normal tissue taken from animals and prepared immediately as a medium for viral growth is termed a(n)

Correct AnswerverifiedShow Answer

A virion is a(n)

Correct AnswerverifiedShow Answer

The terms helical, icosahedral, and complex refer to

Correct AnswerverifiedShow Answer

Prions affect the

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified