Question 1

Diseases such as scrapie in sheep,"mad cow" disease in cattle,and Creutzfeldt-Jakob disease in humans are caused by

Accepted Answer

A)  viroids.
B)  viruses.
C)  retroviruses.
D)  TSEs (transmissible spongiform encephalopathies) .
E)  emerging viruses,for example Ebola.F) C) and E)
G) A) and E)

Question 2

Choose the letter of the best match from the following:
-Bacterial virus.

Accepted Answer

A)  virion
B)  viroid
C)  virus
D)  prion
E)  phageF) D) and E)
G) A) and B)

Question 3

Choose the letter of the best match from the following:
-Infectious,naked RNA.

Accepted Answer

A)  virion
B)  viroid
C)  virus
D)  prion
E)  phageF) B) and E)
G) A) and D)

Question 4

Choose the letter of the best match from the following:
-RNA or DNA enclosed in protein.

Accepted Answer

A)  virion
B)  viroid
C)  virus
D)  prion
E)  phageF) A) and D)
G) A) and E) C

Question 5

The infection cycle of HIV includes all of the following steps except

Accepted Answer

A)  attachment.
B)  entry.
C)  replication.
D)  immediately killing the host cell.
E)  viral DNA integrates into the host chromosomE.F) A) and B)
G) B) and E)

Question 6

An RNA virus that is temperate (lysogenic) would necessarily have to involve all of the following except

Accepted Answer

A)  the enzyme reverse transcriptase.
B)  a prophage.
C)  a lysogen.
D)  oncogenes.
E)  induction.F) D) and E)
G) None of the above

Question 7

Which of the following is not a part of a potential HIV treatment?

Accepted Answer

A)  AZT
B)  protease inhibitors
C)  elimination of susceptible host cells
D)  chemokines and CAF
E)  defective nef geneF) B) and D)
G) A) and E)

Question 8

A layer of lipoprotein and glycoprotein that covers the outer surface of some viruses is the

Accepted Answer

A)  capsid.
B)  casing.
C)  envelope.
D)  membrane.
E)  viroid.F) A) and C)
G) A) and D)

Question 9

The enormous genetic diversity of HIV has made it especially difficult to create a vaccine against the virus.This genetic diversity is largely the result of

Accepted Answer

A)  its large variety of capsid proteins.
B)  the great variety of HIV in the environment.
C)  alternate splicing of exons.
D)  the high error rate of reverse transcriptase.
E)  the high sensitivity of the virus to UV radiation.F) D) and E)
G) C) and E)

Question 10

The integration of a virus into a cellular genome is called _________.

Accepted Answer

The answer of The integration of a virus into a...

Question 11

Phages are viruses that can infect

Accepted Answer

A)  humans.
B)  plants.
C)  insects.
D)  farm animals.
E)  bacteria.F) B) and D)
G) All of the above

Question 12

Activation of a latent herpes virus is responsible for

Accepted Answer

A)  fever blisters.
B)  AIDS.
C)  syphilis.
D)  Alzheimer's disease.
E)  dental caries.F) C) and D)
G) A) and B)

Question 13

The switch from a lysogenic prophage to a lytic cycle is called

Accepted Answer

A)  transformation.
B)  induction.
C)  latency.
D)  phage conversion.
E)  injection.F) A) and B)
G) A) and C)

Question 14

_____________ infects the CD4 + T cells,which are required for normal immunity.

Accepted Answer

The answer of _____________ infects the CD4 + T cells,which...

Question 15

Prions are

Accepted Answer

A)  strands of nucleic acids encased in a protein coat.
B)  viral nucleic acids integrated into the host chromosomes.
C)  viral-infected cells.
D)  infectious proteins with no associated nucleic aciD.
E)  proteins coded by genes.F) D) and E)
G) All of the above D

Question 16

Which of the following statements about the CCR5 and the CXCR4 receptors used by HIV to recognize and enter macrophages is false?

Accepted Answer

A)  The smallpox virus and HIV share the co-receptor CCR5.
B)  Cytokines inhibit HIV infection by binding to CCR5 and CXCR4.
C)  Only HIV with mutated gp120 glycoproteins can bind to CXCR4 receptors on T cells.
D)  Individuals with few CXCR4 receptors should be more resistant to HIV infection.
E)  Individuals with a genetic resistance to smallpox may be more susceptibility to HIV infection.F) A) and C)
G) A) and E) E

Question 17

Viruses that cause lysis of their hosts are called

Accepted Answer

A)  lethal.
B)  potent.
C)  temperate.
D)  virulent.
E)  latent.F) B) and E)
G) C) and D)

Question 18

Benign Vibrio cholerae becomes pathogenic by all of the following steps except

Accepted Answer

A)  a bacteriophage introduces a gene coding for the cholera toxin.
B)  the cholera toxin gene is incorporated into the benign Vibrio cholerae chromosome.
C)  the benign host is transformed into a disease-causing agent by the toxin.
D)  the cholera toxin gene is translateD.
E)  a bacteriophage binds only to benign Vibrio cholerae without pili.F) B) and E)
G) B) and C)

Question 19

Choose the letter of the best match from the following:
-Viral particle.

Accepted Answer

A)  virion
B)  viroid
C)  virus
D)  prion
E)  phageF) A) and E)
G) B) and C)

Question 20

Which of the following is a virus with an icosahedral head,a capsid that contains primarily three proteins,a connecting neck with a collar and long whiskers,a long tail and a complex base plate?

Accepted Answer

A)  influenza virus
B)  measles virus
C)  T2 bacteriophage
D)  HIV
E)  tuberculosisF) C) and D)
G) A) and B)

Exam 27: Viruses

Diseases such as scrapie in sheep,"mad cow" disease in cattle,and Creutzfeldt-Jakob disease in humans are caused by

Correct AnswerverifiedShow Answer

Choose the letter of the best match from the following: -Bacterial virus.

Correct AnswerverifiedShow Answer

Choose the letter of the best match from the following: -Infectious,naked RNA.

Correct AnswerverifiedShow Answer

Choose the letter of the best match from the following: -RNA or DNA enclosed in protein.

Correct AnswerverifiedC

The infection cycle of HIV includes all of the following steps except

Correct AnswerverifiedShow Answer

An RNA virus that is temperate (lysogenic) would necessarily have to involve all of the following except

Correct AnswerverifiedShow Answer

Which of the following is not a part of a potential HIV treatment?

Correct AnswerverifiedShow Answer

A layer of lipoprotein and glycoprotein that covers the outer surface of some viruses is the

Correct AnswerverifiedShow Answer

The enormous genetic diversity of HIV has made it especially difficult to create a vaccine against the virus.This genetic diversity is largely the result of

Correct AnswerverifiedShow Answer

The integration of a virus into a cellular genome is called _________.

Correct AnswerverifiedShow Answer

Phages are viruses that can infect

Correct AnswerverifiedShow Answer

Activation of a latent herpes virus is responsible for

Correct AnswerverifiedShow Answer

The switch from a lysogenic prophage to a lytic cycle is called

Correct AnswerverifiedShow Answer

_____________ infects the CD4 + T cells,which are required for normal immunity.

Correct AnswerverifiedShow Answer

Prions are

Correct AnswerverifiedD

Which of the following statements about the CCR5 and the CXCR4 receptors used by HIV to recognize and enter macrophages is false?

Correct AnswerverifiedE

Viruses that cause lysis of their hosts are called

Correct AnswerverifiedShow Answer

Benign Vibrio cholerae becomes pathogenic by all of the following steps except

Correct AnswerverifiedShow Answer

Choose the letter of the best match from the following: -Viral particle.

Correct AnswerverifiedShow Answer

Which of the following is a virus with an icosahedral head,a capsid that contains primarily three proteins,a connecting neck with a collar and long whiskers,a long tail and a complex base plate?

Correct AnswerverifiedShow Answer

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C

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D

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E

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