Question 1

Which of the following statements best explains why viruses are considered obligate intracellular pathogens?

Accepted Answer

They require host cell energy and machinery to replicate their genome and produce new virions.

Question 2

A scientist isolates a virus with a helical capsid, an RNA genome, and a lipid envelope. Which of the following best describes how this virus is most likely released from the host cell?

Accepted Answer

By budding from the host cell membrane, acquiring its envelope in the process.

Question 3

Which of the following is a consequence of the lack of proofreading activity in RNA-dependent RNA polymerases?

Accepted Answer

RNA viruses exhibit a higher mutation rate, leading to rapid antigenic variation.

Question 4

A patient is diagnosed with a persistent viral infection that is characterized by periods of dormancy and occasional flare-ups. Which virus family is most likely responsible for this infection?

Accepted Answer

Herpesviridae

Question 5

Which of the following best describes antigenic shift in influenza viruses?

Accepted Answer

Major genetic reassortment resulting from coinfection with different strains, potentially leading to pandemics.

Question 6

A virus is found to have a segmented RNA genome. Which process could most likely generate a new viral strain with expanded host range?

Accepted Answer

Antigenic shift via reassortment

Question 7

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

Accepted Answer

Prions are infectious proteins with no genetic material.

Question 8

A laboratory is using a plaque assay to quantify bacteriophages. What does each plaque on the bacterial lawn represent?

Accepted Answer

A single bacteriophage that initiated infection

Question 9

Which of the following antiviral drugs acts by mimicking normal nucleotides and causing premature termination of viral nucleic acid synthesis?

Accepted Answer

Acyclovir

Question 10

A virus is classified as a member of the family Herpesviridae. According to viral taxonomy conventions, what is the correct format for writing the family name?

Accepted Answer

$$	extit{Herpesviridae}$$

Question 11

Which of the following best explains why antiviral drugs are more difficult to develop than antibacterial drugs?

Accepted Answer

Viruses use host cell machinery for replication, so there are fewer unique viral targets.

Question 12

A patient’s blood sample is tested using a latex agglutination assay for a viral antigen. What is the principle behind this test?

Accepted Answer

Viral antigens are linked to latex beads, and agglutination occurs if patient antibodies are present.

Question 13

Which of the following viruses is most likely to cause cancer by integrating its genome into the host cell DNA?

Accepted Answer

Human papilloma virus (HPV)

Question 14

A virus with a broad tropism is most likely to:

Accepted Answer

Infect a wide range of host cells or tissues

Question 15

Which of the following best describes the function of viral spikes (peplomers)?

Accepted Answer

They help the virus attach to and enter specific host cells.

Question 16

A patient is infected with a virus that causes a chronic persistent infection. Which of the following is most likely true about the infection?

Accepted Answer

Virions are continuously released over time, and the disease progresses slowly.

Question 17

Which of the following is a limitation of enzyme-linked immunosorbent assays (ELISAs) for viral detection?

Accepted Answer

They require the antigen to be well characterized and the sample to be a liquid.

Question 18

Which of the following best explains why prion diseases are difficult to diagnose before death?

Accepted Answer

Definitive diagnosis requires detection of sponge-like features in brain tissue, usually collected post-mortem.

Question 19

A new virus is discovered with a genome similar to hepatitis C virus. Animals vaccinated against hepatitis C show a strong immune reaction to the new virus in a latex agglutination test. What does this suggest?

Accepted Answer

The new virus shares antigenic determinants with hepatitis C virus.

Chapter 6 Viruses and Prions: Structure, Replication, and Clinical Relevance

Study Guide - Practice Questions

Study Guide - Flashcards