Question 1

Which of the following statements best describes the genetic material found in viruses?

Accepted Answer

Viruses contain either DNA or RNA, but never both, as their genetic material.

Question 2

A scientist is studying a virus that has a polyhedral nucleocapsid, a helical tail, and attachment fibers. Which type of virus is she most likely examining?

Accepted Answer

A complex bacteriophage

Question 3

Which of the following best explains why prions are resistant to standard sterilization techniques?

Accepted Answer

They are composed solely of misfolded proteins and lack nucleic acids.

Question 4

During the replication cycle of an enveloped animal virus, which process is responsible for the release of new virions without immediately destroying the host cell?

Accepted Answer

Budding (exocytosis)

Question 5

A virus with a segmented, single-stranded RNA genome that is ready for immediate translation upon infection is classified as which type of RNA?

Accepted Answer

Positive-sense RNA ($+\mathrm{ssRNA}$)

Question 6

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

Accepted Answer

Adsorption → Penetration → Replication → Assembly → Maturation → Lysis

Question 7

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

Accepted Answer

They are essential for attachment of the virus to host cell receptors.

Question 8

A patient is diagnosed with cervical cancer caused by a virus. Which term best describes this type of virus?

Accepted Answer

Oncogenic virus

Question 9

Which of the following laboratory methods is most appropriate for cultivating animal viruses for vaccine production?

Accepted Answer

Inoculating fertilized chicken eggs (embryonated eggs)

Question 10

A virus is found to have a capsid made of identical protein subunits arranged in a continuous helix, with its nucleic acid coiled inside. What is the shape of this virus's capsid?

Accepted Answer

Helical

Question 11

Which of the following best explains the process of lysogeny in bacteriophages?

Accepted Answer

The phage genome integrates into the host bacterial chromosome and is replicated along with it without causing immediate lysis.

Question 12

Which of the following is a unique feature of retroviruses such as HIV?

Accepted Answer

They use reverse transcriptase to synthesize DNA from an RNA template.

Question 13

A researcher discovers an infectious agent that consists solely of a short piece of RNA with no protein coat, and it infects plants. What is this agent most likely to be?

Accepted Answer

Viroid

Question 14

Which of the following best describes the difference between a naked virus and an enveloped virus?

Accepted Answer

A naked virus lacks an outer lipid membrane, while an enveloped virus has one derived from the host cell membrane.

Question 15

Which of the following is a possible consequence of lysogenic conversion in bacteria?

Accepted Answer

The bacteria acquire the ability to produce toxins or enzymes that cause disease.

Question 16

A virus is observed to enter a host cell by fusion of its envelope with the host membrane. Which type of virus is this most likely to be?

Accepted Answer

Enveloped animal virus

Question 17

Which of the following best describes the role of the capsid in a virus?

Accepted Answer

It encloses and protects the viral nucleic acid.

Question 18

A patient presents with recurring cold sores. Which type of viral infection is most likely responsible for this clinical presentation?

Accepted Answer

Chronic latent infection

Question 19

Which of the following best explains why antiviral drugs are often more difficult to develop and use safely compared to antibacterial drugs?

Accepted Answer

Viruses use host cell machinery for replication, so drugs targeting viruses can also harm host cells.

Question 20

A laboratory is testing for the presence of a specific virus in a patient sample. Which of the following methods would be most appropriate for directly detecting viral antigens?

Accepted Answer

Antibody-based immunoassay

Chapter 6: Introduction to Viruses, Viroids, and Prions – Structure and Classification

Study Guide - Practice Questions

Study Guide - Flashcards