Question 1

Which of the following best describes the replication strategy of pox viruses?

Accepted Answer

Replication occurs in the cytoplasm and involves complex machinery, making them among the largest and most complex animal viruses.

Question 2

Adenoviruses avoid the synthesis of a lagging strand during DNA replication. Which mechanism allows this?

Accepted Answer

They use a protein primer and replicate their DNA in the nucleus, resulting in continuous synthesis.

Question 3

Which virus is known for producing a single long polyprotein that undergoes self-cleavage to generate multiple functional proteins?

Accepted Answer

Poliovirus

Question 4

What is the role of hemagglutinin in the influenza virus infection cycle?

Accepted Answer

It binds to sialic acid on host cells, facilitating viral entry.

Question 5

Which process describes the generation of new influenza virus strains with a unique set of surface proteins due to reassortment of RNA segments from two distinct viruses?

Accepted Answer

Antigenic shift

Question 6

Retroviruses, such as HIV, use which enzyme to copy their RNA genome into DNA?

Accepted Answer

Reverse transcriptase

Question 7

Which of the following is TRUE about negative-strand RNA animal viruses?

Accepted Answer

They require an RNA replicase enzyme present in the virion to synthesize mRNA.

Question 8

What is a key difference between the replication cycles of polioviruses and coronaviruses?

Accepted Answer

Polioviruses produce a polyprotein, while coronaviruses do not.

Question 9

Which of the following prion diseases is found in deer and elk?

Accepted Answer

Chronic wasting disease

Question 10

Which statement best describes the genetic alteration caused by polyomavirus in nonpermissive host cells?

Accepted Answer

Viral DNA integrates into host DNA, genetically altering the cell and potentially inducing tumor formation.

Question 11

Which class of viral genome requires synthesis of a negative-strand RNA intermediate before new positive strands can be produced?

Accepted Answer

Class IV (ssRNA+)

Question 12

What is the primary medical importance of pox viruses in human history?

Accepted Answer

They have caused devastating epidemics, such as smallpox, and were the first viruses to be eradicated by vaccination.

Question 13

Which of the following is a property of prion proteins that contributes to disease?

Accepted Answer

They are resistant to proteases, insoluble, and tend to aggregate.

Question 14

Which of the following viruses has a segmented genome and can undergo antigenic shift?

Accepted Answer

Influenza virus

Question 15

Which enzyme is present in the virion of negative-strand RNA viruses and is essential for their replication?

Accepted Answer

RNA replicase

Question 16

Which of the following is NOT a prion disease?

Accepted Answer

Measles

Question 17

Which of the following statements about herpesvirus replication is correct?

Accepted Answer

Herpesvirus replication involves three classes of mRNA: immediate early, delayed early, and late proteins.

Question 18

Which of the following best explains antigenic drift in influenza viruses?

Accepted Answer

The structure of neuraminidase and hemagglutinin proteins is subtly altered over time.

Question 19

Which of the following viruses is bullet-shaped, enveloped, and contains a helical nucleocapsid with several enzymes?

Accepted Answer

Rabies virus

Question 20

Which of the following is TRUE regarding the genome structure of RNA viruses?

Accepted Answer

Class IV viruses have a positive-sense single-stranded RNA genome that can be directly translated.

11. Viral Genomes, Replication Strategies, and Subviral Agents: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard