Question 1

Which of the following best describes the mechanism by which an enveloped animal virus typically exits its host cell?

Accepted Answer

By budding, acquiring a portion of the host cell membrane as its envelope

Question 2

A scientist is culturing a virus that requires the host cell's nucleus for replication. Which type of virus is most likely being studied?

Accepted Answer

A DNA virus

Question 3

Which of the following is a key difference between bacteriophage and animal virus replication?

Accepted Answer

Animal viruses may enter host cells by membrane fusion, while bacteriophages do not.

Question 4

Which of the following is NOT a mechanism by which animal viruses can enter host cells?

Accepted Answer

Binary fission

Question 5

A patient is diagnosed with a disease caused by a prion. Which of the following statements about prions is correct?

Accepted Answer

Prions are infectious proteins that cause normal cellular proteins to misfold into a disease-causing form.

Question 6

Which of the following best explains why viroids are pathogenic in plants?

Accepted Answer

Viroid RNA adheres to complementary plant RNA, leading to degradation by plant enzymes and resulting in disease.

Question 7

Which of the following laboratory methods is most commonly used to estimate the number of bacteriophages in a sample?

Accepted Answer

Plaque assay

Question 8

A retrovirus differs from other RNA viruses in that it:

Accepted Answer

Uses reverse transcriptase to synthesize DNA from its RNA genome

Question 9

Which of the following is a real-world example of a cancer known to be caused by a virus?

Accepted Answer

Cervical cancer

Question 10

Which of the following statements about the sterilization of prions is correct?

Accepted Answer

Prions are destroyed by incineration or autoclaving in concentrated sodium hydroxide.

Question 11

Which of the following best describes the process of latency in animal viruses?

Accepted Answer

The viral genome remains dormant in the host cell, sometimes integrating into host DNA, and may reactivate later.

Question 12

Which of the following is a reason why embryonated chicken eggs are used for culturing viruses?

Accepted Answer

They are inexpensive, free of contaminating microbes, and provide a nourishing environment.

Question 13

Which of the following is a plausible outcome if a virus inserts its genome into the repressor gene of a host cell, according to the oncogene theory?

Accepted Answer

The cell may lose tumor repression, leading to uncontrolled cell division and cancer.

Question 14

Which of the following is a characteristic unique to prions compared to viruses and viroids?

Accepted Answer

They are infectious proteins that lack nucleic acids.

Question 15

Which of the following is a correct comparison between viruses, viroids, and prions?

Accepted Answer

Viruses contain nucleic acids and a protein coat, viroids contain only RNA, and prions contain only protein.

Question 16

Which of the following best explains why viruses cannot be cultured in standard microbiological media?

Accepted Answer

Viruses require living host cells for replication.

Question 17

A scientist observes large vacuoles forming in the brain tissue of an animal, giving it a spongy appearance. Which infectious agent is most likely responsible?

Accepted Answer

A prion

Question 18

Which of the following is a plausible reason why laboratory animals are not always the preferred method for culturing animal viruses?

Accepted Answer

They are expensive to maintain and raise ethical concerns.

Question 19

Which of the following is a correct statement about the replication of RNA viruses in animal cells?

Accepted Answer

Most RNA viruses replicate in the cytoplasm of the host cell.

Question 20

Which of the following is a plausible reason why some vaccines are prepared in embryonated chicken eggs?

Accepted Answer

Embryonated eggs provide a sterile, nutrient-rich environment ideal for viral growth.

Characterizing and Classifying Viruses, Viroids, and Prions: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards