Deck 23: Viruses, Viroids, and Prions: Infectious Biological Particles

Question 1

In the figure, which number identifies the viral genome?

A)2
B)3
C)4
D)5

Answer 1

A

Question 2

What is the protein layer surrounding the viral genome called?

A)a cell membrane
B)a capsid
C)an envelope
D)a capsule

Answer 2

B

Question 3

Which of the following viruses has a double stranded DNA genome?

A)the flavivirus
B)the retrovirus
C)the orthomyxovirus
D)the poxvirus

Answer 3

D

Question 4

What is the viral DNA that is integrated into a bacterial host chromosome called?

A)a microphage
B)a spike
C)an endospore
D)a prophage

Question 5

In the figure, which number identifies the sheath?

A)2
B)3
C)4
D)5

Question 6

In which cycle does the virus kill the infected host cell?

A)in the lytic cycle
B)in the phagocytic cycle
C)in the endocytic cycle
D)in the lysogenic cycle

Question 7

Which describes the latent phase of an animal virus?

A)the time it takes to replicate the viral genome
B)the equivalent of the lysogenic cycle of some bacteriophages
C)the period from infection to host cell lysis
D)the time it takes to assemble one viral particle

Question 8

In which major family of animal viruses is the virus that causes polio found?

A)in orthomyxovirus
B)in enterovirus
C)in adenovirus
D)in retrovirus

Question 9

In which major family of animal viruses is the virus that causes AIDS found?

A)in orthomyxovirus
B)in adenovirus
C)in flavivirus
D)in retrovirus

Question 10

How are viruses different from bacteria?

A)They have a single type of nucleic acid.
B)They may be pathogenic to humans.
C)They do not contain protein.
D)They are too small to be seen with the unaided eye.

Question 11

Which term best describes the shape of the virus in the figure?

A)helical
B)icosahedral
C)enveloped
D)complex

Question 12

Which term best describes the biological nature of a virus?

A)lipid
B)rapidly dividing tissue
C)living cell
D)infectious particle

Question 13

Which equation best describes the composition of the simplest type of viral particle?

A)nucleic acid + capsid + protein spikes
B)nucleic acid + capsid
C)nucleic acid only
D)nucleic acid + envelope

Question 14

In the figure, which number identifies the structure that binds to the host cell?

A)6
B)5
C)4
D)1

Question 15

In the figure, which number identifies the coat?

A)1
B)2
C)3
D)4

Question 16

Why are viruses considered nonliving?

A)because they lack a cell wall
B)because they cannot reproduce outside a host cell
C)because they lack a nucleus
D)because they contain RNA as their genetic material

Question 17

In the figure, which virus is illustrated?

A)human immunodeficiency virus
B)tobacco mosaic virus
C)herpesvirus
D)bacteriophage

Question 18

In which major family of animal viruses is the virus that causes influenza found?

A)in adenovirus
B)in papillomavirus
C)in flavivirus
D)in orthomyxovirus

Question 19

In the figure, which number identifies the structure that enters the host cell?

A)5
B)3
C)2
D)1

Question 20

In the figure, which number identifies the head?

A)5
B)4
C)2
D)1

Question 21

What is the function of reverse transcriptase?

A)to synthesize viral protease
B)to make RNA from DNA
C)to make DNA from RNA
D)to assemble HIV protein spikes

Question 22

Viral progeny are synthesized as small particles that grow to adult size.

Question 23

Viroids consist of only RNA molecules.

Question 24

What adaptation helped the strain of influenza responsible for the pandemic of 1918 to be such an effective infectious agent?

A)resistance to antibiotics
B)airborne mode of transmission
C)mutations in polymerase genes
D)unique protein spikes

Question 25

Influenza is caused by a DNA virus.

Question 26

Viruses are too small to carry any enzymes of their own.

Question 27

BSE is caused by an infections protein molecule.

Question 28

All enveloped animal viruses have protein spikes.

Question 29

Animal viruses without envelopes enter the host cell via fusion with the cell membrane.

Question 30

Creutzfeldt-Jakob disease (CJD) is a fatal prion infection in humans.

Question 31

Viral infections in plants are spread from cell to cell via plasmodesmata.

Question 32

Polio virus is often used in genetic research.

Question 33

Which prion disease affects sheep?

A)kuru
B)scrapie
C)muru
D)bovine spongiform encephalopathy

Question 34

In which viruses are envelopes most commonly found?

A)in viruses of animals
B)in viruses of bacteria
C)in viruses of plants
D)in viruses of archaea

Question 35

What type of molecule are viroids composed of?

A)protein
B)DNA
C)carbohydrate
D)RNA

Question 36

Some viruses can cause cancer.

Question 37

Who is credited with the discovery of prions as a new biological principle of infection?

A)Carl Louis
B)Stanley Brenner
C)Stanley Prusiner
D)Carl Woese

Question 38

Evidence suggests that viruses evolved only after the evolution of cells.

Question 39

Which protein or enzyme would be a good target for anti-HIV therapy?

A)DNA polymerase
B)DNA ligase
C)reverse transcriptase
D)RNA polymerase

Question 40

Viral genomes are difficult to sequence.

Question 41

Why are viral infections so much more difficult to treat than bacterial infections?