Deck 22: Viruses, Viroids, and Prions: Infectious Biological Particles

Question 1

Figure 22-1
In Figure 22-1, which number identifies the head?

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

Answer 1

D

Question 2

In which types of viruses are envelopes most commonly found?

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

Answer 2

A

Question 3

Figure 22-1
In Figure 22-1, which number identifies the sheath?

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

Answer 3

D

Question 4

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

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

Question 5

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 6

Figure 22-1
Which of these terms best describes the shape of the virus in Figure 22-1?

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

Question 7

Figure 22-1
In Figure 22-1, which number identifies the coat?

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

Question 8

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 9

What is the protein layer surrounding the viral genome called?

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

Question 10

Figure 22-1
In Figure 22-1, which number identifies the viral genome?

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

Question 11

Which of these terms best describes the biological nature of a virus?

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

Question 12

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

A) Orthomyxoviridae
B) Adenoviridae
C) Flaviviridae
D) Retroviridae

Question 13

Figure 22-1
In Figure 22-1, which virus is illustrated?

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

Question 14

Figure 22-1
In Figure 22-1, which number identifies the structure that binds to the host cell?

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

Question 15

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

A) Orthomyxoviridae
B) Picornaviridae
C) Rhabdoviridae
D) Poxviridae

Question 16

Figure 22-1
In Figure 22-1, which number identifies the structure that enters the host cell?

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

Question 17

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 18

Which of these viruses has a double-stranded DNA genome?

A) Flavivirus
B) retrovirus
C) orthomyxovirus
D) poxvirus

Question 19

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

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

Question 20

Which of these statements 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 21

BSE is caused by an infections protein molecule.

Question 22

What type of molecule are viroids composed of?

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

Question 23

Viral genomes are difficult to sequence.

Question 24

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

Question 25

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 26

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

Question 27

All enveloped animal viruses have protein spikes.

Question 28

Viroids consist of only RNA molecules.

Question 29

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

Question 30

Influenza is caused by a DNA virus.

Question 31

Some viruses can cause cancer.

Question 32

Which prion disease affects sheep?

A) kuru
B) scrapie
C) chronic wasting disease
D) bovine spongiform encephalopathy

Question 33

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 34

Polio virus is often used in genetic research.

Question 35

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

Question 36

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

Question 37

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

Question 38

Why is hepatitis C a serious disease?

A) It causes nausea.
B) It is heritable.
C) It causes cirrhosis and/or cancer.
D) It causes yellow skin hue.