Question 1

Which of the following best describes the role of a viral capsid?

Accepted Answer

It is the protein coat that surrounds and protects the viral genome.

Question 2

A bacteriophage infects a bacterial cell and integrates its DNA into the host genome without killing the cell. What is this phase called?

Accepted Answer

Lysogenic cycle

Question 3

Which enzyme is responsible for converting viral RNA into DNA in retroviruses?

Accepted Answer

Reverse transcriptase

Question 4

A virus with a positive-sense RNA genome can immediately begin which process upon entering a host cell?

Accepted Answer

Translation of viral proteins

Question 5

Which of the following is TRUE about prions?

Accepted Answer

They are infectious proteins that can cause brain diseases.

Question 6

During the lytic cycle, what happens to the host cell?

Accepted Answer

It is destroyed as new viral particles are released.

Question 7

Which of the following best explains why viroids are unique among infectious agents?

Accepted Answer

They consist solely of short, circular, single-stranded RNA and do not encode proteins.

Question 8

A virus infects a cell and uses the host's ribosomes, nucleotides, and amino acids to produce new viral particles. This process is called:

Accepted Answer

Viral replication

Question 9

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

Accepted Answer

Attachment → Injection of DNA → Host DNA degradation → Synthesis of viral components → Assembly → Release

Question 10

Which statement best describes the difference between a virulent phage and a temperate phage?

Accepted Answer

A virulent phage only undergoes the lytic cycle, while a temperate phage can undergo both lytic and lysogenic cycles.

Question 11

Which of the following equations correctly represents the transcription of viral RNA to DNA by reverse transcriptase?

Accepted Answer

$$\mathrm{RNA} \xrightarrow{\mathrm{reverse\ transcriptase}} \mathrm{DNA}$$

Question 12

A double-stranded DNA virus infects a human cell. Where does its genome typically replicate?

Accepted Answer

In the nucleus during S phase of the cell cycle

Question 13

Which of the following is a real-world example of a retrovirus?

Accepted Answer

Human Immunodeficiency Virus (HIV)

Question 14

Which process allows animal viruses to enter host cells by fusing their membranes with the host's membrane?

Accepted Answer

Membrane fusion

Question 15

A negative-sense RNA virus must carry which enzyme to be infectious?

Accepted Answer

Viral RNA polymerase

Question 16

Which of the following best explains why restriction enzymes are important in bacterial defense against viruses?

Accepted Answer

They degrade viral DNA, preventing replication.

Question 17

Which of the following is NOT a component of a typical animal virus with an envelope?

Accepted Answer

Ribosome

Question 18

Which infectious agent is most likely to disrupt plant growth without encoding any proteins?

Accepted Answer

Viroid

Question 19

Which of the following best describes the function of glycoproteins on the surface of animal viruses?

Accepted Answer

They mediate attachment to specific receptors on host cells.

Question 20

A scientist observes a virus that can infect both plants and animals, and its genome is single-stranded RNA. Which Baltimore classification group does this virus most likely belong to?

Accepted Answer

Group IV: (+)ssRNA viruses

Viruses and Other Infectious Agents: Structure, Replication, and Diversity

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