Question 1

Which of the following statements best differentiates viruses from bacteria?

Accepted Answer

Viruses require living host cells to multiply, while bacteria can reproduce independently.

Question 2

A scientist is attempting to culture a newly discovered virus. Which of the following methods would be most appropriate for viral cultivation?

Accepted Answer

Inoculating the virus into a living animal or embryonated egg.

Question 3

Which of the following best describes the structure labeled as 'spike glycoprotein (S)' on the SARS-CoV-2 virion?

Accepted Answer

It is a projection from the outer surface that facilitates attachment to host cells.

Question 4

Which of the following is a unique feature of prions compared to viruses?

Accepted Answer

Prions are proteinaceous infectious particles without nucleic acids.

Question 5

A patient is suspected of having a viral infection. Which laboratory test would most rapidly detect the presence of viral nucleic acid in the sample?

Accepted Answer

Polymerase chain reaction (PCR)

Question 6

Which of the following best explains why continuous cell lines are preferred over primary cell lines for culturing viruses?

Accepted Answer

Continuous cell lines can be maintained through many generations, providing a consistent supply of host cells.

Question 7

During the lysogenic cycle of a bacteriophage, which of the following events occurs?

Accepted Answer

The phage DNA integrates into the host chromosome and is replicated along with it.

Question 8

Which of the following best describes the process of specialized transduction?

Accepted Answer

A phage transfers specific bacterial genes adjacent to the prophage site to another bacterium.

Question 9

Which of the following viruses is associated with the development of cervical cancer?

Accepted Answer

Human papillomavirus (HPV)

Question 10

A patient presents with cold sores that recur during periods of stress. This is an example of which type of viral infection?

Accepted Answer

Latent viral infection

Question 11

Which of the following best describes the role of reverse transcriptase in the replication of retroviruses?

Accepted Answer

It synthesizes DNA from an RNA template.

Question 12

Which of the following is a characteristic of all viruses but not of bacteria?

Accepted Answer

Obligate intracellular parasite

Question 13

Which of the following best explains why viruses are not sensitive to antibiotics?

Accepted Answer

Viruses lack cell walls and metabolic pathways targeted by antibiotics.

Question 14

A patient is tested for a recent viral infection. The laboratory detects high levels of IgM antibodies but low levels of IgG. What does this indicate?

Accepted Answer

The patient is in the early stages of a primary infection.

Question 15

Which of the following is true regarding the multiplication of animal viruses compared to bacteriophages?

Accepted Answer

Animal viruses may enter host cells by receptor-mediated endocytosis or fusion.

Question 16

Which of the following best describes the eclipse period in the one-step growth curve of a virus?

Accepted Answer

The period when no infectious virions are detected in the extracellular environment.

Question 17

Which of the following viruses is classified as a single-stranded RNA, + strand, enveloped virus?

Accepted Answer

SARS-CoV-2

Question 18

Which of the following is a real-world consequence of lysogenic conversion in bacteria?

Accepted Answer

The bacterium acquires the ability to produce a toxin, such as Vibrio cholerae producing cholera toxin.

Question 19

Which of the following best explains how an RNA virus can cause cancer in humans?

Accepted Answer

The RNA virus uses reverse transcriptase to synthesize DNA, which then integrates into the host genome.

Question 20

Which of the following diseases is caused by a prion?

Accepted Answer

Creutzfeldt-Jakob disease (CJD)

Viruses, Viroids, and Prions: Structure, Classification, and Pathogenicity

Study Guide - Practice Questions

Study Guide - Flashcards