Question 1

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

Accepted Answer

It is the protein coat that covers the viral genome and may have different forms.

Question 2

A bacteriophage is a virus that specifically infects which type of organism?

Accepted Answer

Bacteria

Question 3

Which of the following is TRUE regarding the lytic cycle of a bacteriophage?

Accepted Answer

The phage replicates its DNA, degrades the host DNA, and new viral components are synthesized, leading to host cell lysis.

Question 4

Which enzyme is unique to retroviruses and is responsible for synthesizing DNA from an RNA template?

Accepted Answer

Reverse transcriptase

Question 5

A virus with a positive-sense single-stranded RNA genome can immediately do which of the following upon entering a host cell?

Accepted Answer

Serve as mRNA and be translated by host ribosomes

Question 6

Which of the following best describes a viroid?

Accepted Answer

A small, circular, single-stranded RNA pathogen that infects plants

Question 7

Which of the following is a key difference between the lytic and lysogenic cycles?

Accepted Answer

The lytic cycle results in host cell lysis, while the lysogenic cycle integrates viral DNA into the host genome.

Question 8

Which of the following statements about prions is correct?

Accepted Answer

Prions are infectious proteins that can cause brain diseases in animals.

Question 9

Which step is NOT part of the general process of animal virus replication?

Accepted Answer

Integration of viral DNA into the host chromosome is required for all animal viruses.

Question 10

A scientist discovers a new virus that uses host RNA polymerase to transcribe its genome directly into mRNA. Which type of viral genome does this virus most likely possess?

Accepted Answer

Double-stranded DNA

Question 11

Which of the following best explains why antibiotics are ineffective against viruses?

Accepted Answer

Viruses lack the cellular structures and metabolic pathways targeted by antibiotics.

Question 12

Which of the following is a correct sequence of events in the replication of a retrovirus?

Accepted Answer

Entry → Reverse transcription → Integration into host DNA → Transcription → Translation

Question 13

A virus infects a host cell and its genome is immediately translated by host ribosomes. Which type of viral genome does this virus most likely have?

Accepted Answer

Positive-sense single-stranded RNA

Question 14

Which of the following best describes the role of viral envelope glycoproteins?

Accepted Answer

They mediate attachment and entry into host cells by binding to specific receptors.

Question 15

Which of the following is a plausible outcome if a bacteriophage enters the lysogenic cycle?

Accepted Answer

The phage DNA integrates into the host chromosome and is replicated along with host DNA.

Question 16

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

Accepted Answer

They consist solely of small, circular, single-stranded RNA without a protein coat.

Question 17

Which of the following statements about negative-sense RNA viruses is correct?

Accepted Answer

Their genomes must first be transcribed into complementary positive-sense RNA before translation.

Question 18

Which of the following is a real-world example of a prion disease?

Accepted Answer

Creutzfeldt-Jakob disease

Question 19

Which of the following best describes the process of viral genome integration during the lysogenic cycle?

Accepted Answer

Viral DNA is incorporated into the host cell's chromosome and replicated with host DNA.

Question 20

Which of the following equations best represents the transcription of a double-stranded DNA virus genome into mRNA?

Accepted Answer

$$\mathrm{DNA} \xrightarrow{	ext{RNA\ Polymerase}} \mathrm{mRNA}$$

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