Question 1

Which of the following statements best explains why RNA viruses tend to mutate more rapidly than DNA viruses?

Accepted Answer

RNA polymerases lack proofreading capabilities, allowing mutations to accumulate during replication.

Question 2

A scientist is studying a virus with a segmented RNA genome that can undergo reassortment. Which of the following best describes a possible consequence of this process?

Accepted Answer

The virus can generate new strains with mixed genetic material from different parental viruses, potentially leading to antigenic shift.

Question 3

Which of the following best describes the function of the viral spikes (peplomers) found on the surface of many animal viruses?

Accepted Answer

They are glycoprotein extensions that help the virus attach to and gain entry into host cells.

Question 4

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

Accepted Answer

Herpesviridae

Question 5

During the lytic replication cycle of a bacteriophage, which enzyme is responsible for breaking down the bacterial cell wall to release new virions?

Accepted Answer

Lysozyme

Question 6

Which of the following best describes the process of antigenic drift in influenza viruses?

Accepted Answer

Minor genetic changes in the HA and NA spike proteins due to mutations during replication.

Question 7

A virus with a single-stranded negative-sense RNA genome must first perform which step before its genome can be translated by host ribosomes?

Accepted Answer

Transcribe its genome into complementary mRNA using RNA-dependent RNA polymerase.

Question 8

Which of the following is a key difference between naked and enveloped animal viruses in their release from host cells?

Accepted Answer

Enveloped viruses are released by budding, while naked viruses are released by host cell lysis.

Question 9

Which of the following best explains why prions are unique among infectious agents?

Accepted Answer

They are infectious proteins that lack genetic material and do not replicate.

Question 10

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

Accepted Answer

A single bacteriophage in the initial sample that infected and lysed bacterial cells.

Question 11

Which of the following antiviral drugs acts as a nucleoside analog to inhibit viral DNA replication, and is commonly used to treat herpes simplex virus infections?

Accepted Answer

Acyclovir

Question 12

A virus is classified as having a helical capsid, a segmented single-stranded RNA genome, and an envelope. According to the International Committee on Taxonomy of Viruses (ICTV), which properties are used to classify this virus?

Accepted Answer

Type of nucleic acid, capsid symmetry, presence or absence of envelope, and genome architecture.

Question 13

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

Accepted Answer

It synthesizes double-stranded DNA from a single-stranded RNA genome.

Question 14

A patient receives a postexposure prophylaxis treatment after a potential rabies exposure. What is the main component of this treatment?

Accepted Answer

A mixture of injectable antibodies targeting the virus.

Question 15

Which of the following laboratory techniques is most appropriate for detecting very low levels of viral nucleic acid in a clinical sample?

Accepted Answer

Polymerase chain reaction (PCR)

Question 16

A virus infects only human respiratory epithelial cells and not other tissues or species. This specificity is best described as:

Accepted Answer

Narrow tropism

Question 17

Which of the following is a correct sequence of steps in the lytic replication cycle of a bacteriophage?

Accepted Answer

Attachment → Penetration → Replication → Assembly → Release

Question 18

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

Accepted Answer

They require host cell energy and machinery to replicate.

Question 19

A scientist is developing a vaccine using a weakened version of a virus that no longer causes disease but still stimulates an immune response. This type of viral strain is best described as:

Accepted Answer

Attenuated

Question 20

Which of the following best describes the function of the eukaryotic glycocalyx?

Accepted Answer

It promotes or prevents cell adhesion and plays a role in cell communication.

Viruses and Prions: Structure, Replication, and Clinical Applications

Study Guide - Practice Questions

Study Guide - Flashcards