Question 1

Which of the following best distinguishes viruses from bacteria?

Accepted Answer

Viruses are obligate intracellular parasites and lack ribosomes, while bacteria can reproduce independently and have ribosomes.

Question 2

A scientist is studying a virus with a helical capsid and no envelope. Which of the following viruses is most likely being studied?

Accepted Answer

Tobacco mosaic virus (TMV)

Question 3

Which of the following steps is unique to the multiplication of animal viruses compared to bacteriophages?

Accepted Answer

Uncoating of the capsid by host or viral enzymes

Question 4

A patient presents with cold sores that recur periodically. Which type of viral infection does this represent?

Accepted Answer

Latent viral infection

Question 5

Which of the following is a correct pairing of viral taxonomy?

Accepted Answer

Herpesviridae (family) – Herpesvirus (genus) – HHV-1 (species)

Question 6

Which laboratory method is most appropriate for quantifying the number of infectious bacteriophage particles in a sample?

Accepted Answer

Plaque assay

Question 7

Which of the following best describes the lysogenic cycle of bacteriophage lambda?

Accepted Answer

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

Question 8

Which of the following is a property of prions but NOT of viruses?

Accepted Answer

Can be inactivated by proteases

Question 9

A researcher is using continuous cell lines to culture animal viruses. What is a major advantage of continuous cell lines over primary cell lines?

Accepted Answer

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

Question 10

Which of the following is an example of a disease caused by a viroid?

Accepted Answer

Potato spindle tuber disease

Question 11

Which of the following best explains why antibiotics are ineffective against viruses?

Accepted Answer

Viruses lack peptidoglycan cell walls targeted by antibiotics.

Question 12

Which of the following is a step in the lytic cycle of a T-even bacteriophage but NOT in the lysogenic cycle?

Accepted Answer

Immediate lysis and release of new virions

Question 13

Which of the following is a characteristic of an enveloped virus?

Accepted Answer

It has a lipid, protein, and carbohydrate coating derived from the host cell membrane.

Question 14

Which of the following is a correct statement about oncogenic viruses?

Accepted Answer

They can integrate their genetic material into the host genome, potentially leading to tumor formation.

Question 15

Which of the following is a method used to identify viruses in clinical samples?

Accepted Answer

Serological tests such as Western blotting

Question 16

A virus is found to have a polyhedral capsid and is nonenveloped. Which of the following viruses fits this description?

Accepted Answer

Papillomavirus

Question 17

Which of the following best describes specialized transduction?

Accepted Answer

Transfer of specific bacterial genes by a lysogenic phage

Question 18

Which of the following is a property of a latent viral infection?

Accepted Answer

The virus remains dormant in host cells and may reactivate later.

Question 19

Which of the following is true regarding the host range of viruses?

Accepted Answer

The host range is determined by specific attachment sites and cellular factors.

Question 20

Which of the following is a disease caused by a prion?

Accepted Answer

Creutzfeldt-Jakob disease

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

Study Guide - Practice Questions