Question 1

Which of the following best describes the genome of the virus shown in the first image (a highly structured, non-enveloped icosahedral particle)?

Accepted Answer

Positive-sense single-stranded RNA

Question 2

Which virus is most likely represented by the first image, based on its structure and the diseases it causes?

Accepted Answer

Poliovirus

Question 3

Which of the following statements about the replication of positive-sense single-stranded RNA (+ssRNA) viruses is correct?

Accepted Answer

Their RNA genome can be directly used by host ribosomes to synthesize viral proteins.

Question 4

Which of the following equations correctly represents the central dogma of molecular biology, and which enzyme allows retroviruses to violate this dogma?

Accepted Answer

$$DNA \rightarrow RNA \rightarrow Protein$$, enzyme: Reverse transcriptase

Question 5

Which of the following best explains why influenza vaccines must be updated annually?

Accepted Answer

Influenza virus undergoes rapid antigenic drift and shift due to mutations and genome segment reassortment.

Question 6

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

Accepted Answer

Animal viruses require uncoating of the capsid, while bacteriophages do not.

Question 7

A patient is diagnosed with HIV. Which step in the HIV life cycle is responsible for the establishment of viral latency?

Accepted Answer

Integration of viral DNA into the host genome

Question 8

Which of the following viruses is transmitted primarily by mosquitoes and is zoonotic in origin?

Accepted Answer

West Nile virus

Question 9

Which of the following best describes the mechanism of release for enveloped animal viruses?

Accepted Answer

Budding from the host cell membrane

Question 10

Which of the following equations best represents the process by which retroviruses replicate their genome?

Accepted Answer

$$+ssRNA \xrightarrow{reverse\ transcriptase} dsDNA \xrightarrow{integration} host\ genome$$

Question 11

Which of the following viruses is most likely to cause paralysis as a long-term complication?

Accepted Answer

Poliovirus

Question 12

Which of the following best explains why antiretroviral therapy for HIV must be continued for life?

Accepted Answer

HIV establishes a reservoir of latently infected cells with integrated provirus.

Question 13

Which of the following is a unique feature of the coronavirus life cycle compared to other +ssRNA viruses?

Accepted Answer

Assembly of new virions at the endoplasmic reticulum and release through the Golgi apparatus

Question 14

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

Accepted Answer

Reassortment of genome segments between different influenza strains

Question 15

Which of the following viruses is a double-stranded RNA virus that causes severe diarrhea in children?

Accepted Answer

Rotavirus

Question 16

Which of the following best explains why having HIV does not necessarily mean a person has AIDS?

Accepted Answer

AIDS is defined by the onset of severe immune dysfunction and opportunistic infections, which may not occur immediately after HIV infection.

Question 17

Which of the following is a common vector for the transmission of Zika, Dengue, and Yellow Fever viruses?

Accepted Answer

Mosquitoes

Question 18

Which of the following best describes the process of viral uncoating in animal viruses?

Accepted Answer

The capsid is removed by host cell enzymes after entry.

Question 19

Which of the following is a reason why polio cases have dramatically decreased worldwide?

Accepted Answer

Widespread administration of effective vaccines

Question 20

Which of the following best describes the nature of chronic infection for animal viruses such as HIV?

Accepted Answer

Latency with or without incorporation into host DNA; incorporation is permanent

lec 20

Study Guide - Practice Questions

Study Guide - Flashcards