Question 1

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

Accepted Answer

Viruses may contain either DNA or RNA, but never both.

Question 2

What is the primary function of the viral capsid?

Accepted Answer

To protect viral nucleic acid and facilitate attachment to host cells.

Question 3

Which of the following best explains why viruses are considered acellular?

Accepted Answer

They lack cytoplasmic membrane, cytosol, and organelles.

Question 4

During the lytic replication cycle of a bacteriophage, what is the correct order of events?

Accepted Answer

Attachment, entry, synthesis, assembly, release

Question 5

Which of the following is a unique feature of enveloped viruses compared to non-enveloped viruses?

Accepted Answer

They acquire a phospholipid bilayer from the host cell during replication or release.

Question 6

A virus that can infect many different types of cells in various hosts is best described as:

Accepted Answer

A generalist virus

Question 7

Which of the following best describes the process of lysogeny in bacteriophages?

Accepted Answer

The phage genome integrates into the host chromosome and replicates with it without causing immediate lysis.

Question 8

Which of the following is a correct statement about prions?

Accepted Answer

Prions are proteinaceous infectious agents that cause spongiform encephalopathies.

Question 9

Which of the following is a real-world example of a disease caused by a virus carrying oncogenes?

Accepted Answer

Cervical cancer

Question 10

Which laboratory method is commonly used to culture animal viruses and is also used in vaccine production?

Accepted Answer

Injection into embryonated chicken eggs

Question 11

Which of the following best explains why enveloped viruses are often more sensitive to environmental conditions than non-enveloped viruses?

Accepted Answer

Their phospholipid envelope is susceptible to desiccation, heat, and detergents.

Question 12

Which of the following is NOT a step in the lytic replication cycle of bacteriophages?

Accepted Answer

Lysogeny

Question 13

A patient is diagnosed with a fatal neurological disease characterized by large vacuoles in the brain and a spongy appearance. Which infectious agent is most likely responsible?

Accepted Answer

A prion

Question 14

Which of the following statements about viroids is correct?

Accepted Answer

Viroids are small, circular pieces of RNA that infect plants.

Question 15

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

Accepted Answer

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

Question 16

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

Accepted Answer

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

Question 17

Which of the following best explains why viruses are not considered alive by some scientists?

Accepted Answer

They cannot reproduce independently and lack cellular structure.

Question 18

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 phage genes.

Question 19

Which of the following is the best method to destroy prions in contaminated surgical instruments?

Accepted Answer

Autoclaving in 1 M NaOH solution

Question 20

A scientist observes a virus with a helical capsid and an envelope. Which of the following best describes how this virus is likely released from the host cell?

Accepted Answer

By budding from the host cell membrane

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

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