Question 1

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

Accepted Answer

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

Question 2

A scientist is studying a virus with a helical capsid and an envelope. Which of the following is most likely true about this virus?

Accepted Answer

It acquires its envelope from the host cell membrane during replication or release.

Question 3

Which of the following best explains why viruses are not considered living organisms by all scientists?

Accepted Answer

They are unable to replicate outside of a host cell.

Question 4

A bacteriophage infects a bacterial cell and integrates its genome into the host chromosome, remaining dormant for several generations. What is this process called?

Accepted Answer

Lysogeny

Question 5

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

Accepted Answer

Attachment → Entry → Synthesis → Assembly → Release

Question 6

Which of the following is a unique feature of prions compared to viruses?

Accepted Answer

Prions are composed solely of protein and lack nucleic acids.

Question 7

A patient is diagnosed with a cancer that is known to be associated with a viral infection. Which of the following viruses is LEAST likely to be the cause?

Accepted Answer

Influenza virus

Question 8

Which of the following laboratory methods is most suitable for growing large quantities of viruses for vaccine production?

Accepted Answer

Culturing viruses in embryonated chicken eggs

Question 9

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

Accepted Answer

The virus acquires its envelope from the host cell membrane as it exits the cell.

Question 10

Which of the following statements about viroids is correct?

Accepted Answer

Viroids are small, circular pieces of RNA that infect plants and lack a protein capsid.

Question 11

A virus is classified as a generalist. What does this mean?

Accepted Answer

It can infect many kinds of cells in many different hosts.

Question 12

Which of the following is a plausible reason why prion diseases are difficult to eliminate from contaminated surgical instruments?

Accepted Answer

Prions are only destroyed by incineration or autoclaving in 1 M NaOH.

Question 13

Which of the following best explains why animal viruses often use endocytosis to enter host cells?

Accepted Answer

Animal cells lack a cell wall, allowing the entire virus to be engulfed by the membrane.

Question 14

Which of the following is a key difference between the replication of DNA and RNA animal viruses?

Accepted Answer

DNA viruses often replicate in the nucleus, while RNA viruses often replicate in the cytoplasm.

Question 15

A scientist observes a mass of cells dividing uncontrollably after infection with a certain virus. Which process is most likely occurring?

Accepted Answer

Neoplasia

Question 16

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

Accepted Answer

Viruses are classified based on type of nucleic acid, presence of envelope, shape, and size.

Question 17

Which of the following best describes the role of viral glycoproteins in the infection process?

Accepted Answer

They mediate attachment to host cell receptors.

Question 18

A patient presents with symptoms of spongiform encephalopathy. Which of the following is the most likely causative agent?

Accepted Answer

Prion

Question 19

Which of the following best explains why some animal viruses can remain dormant in host cells for years?

Accepted Answer

They can enter a latent state, during which there is no viral activity.

Question 20

Which of the following is a plausible outcome of lysogenic conversion in bacteria?

Accepted Answer

The bacterium acquires new traits, such as toxin production, due to genes carried by the prophage.

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

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