Question 1

Which of the following statements best describes why viruses are considered acellular?

Accepted Answer

They lack a cytoplasmic membrane, cytosol, and organelles.

Question 2

A scientist discovers a new infectious agent that contains single-stranded RNA, a protein coat, and no organelles. Which property confirms it is a virus?

Accepted Answer

It recruits the host cell's metabolic pathways for replication.

Question 3

Which component of a virion is responsible for host cell recognition and attachment?

Accepted Answer

Envelope glycoproteins (spikes)

Question 4

Viruses are classified based on several criteria. Which of the following is NOT a criterion used for virus classification?

Accepted Answer

Ability to perform metabolic pathways

Question 5

Which of the following best explains why enveloped viruses are generally more fragile than naked viruses?

Accepted Answer

Their phospholipid bilayer envelope is sensitive to environmental conditions.

Question 6

During the lytic replication cycle, which stage immediately follows the entry of the viral genome into the host cell?

Accepted Answer

Synthesis

Question 7

A bacteriophage infects a bacterial cell and integrates its genome into the host's DNA, remaining inactive for several generations. What is this state called?

Accepted Answer

Prophage

Question 8

Which of the following mechanisms is NOT a way animal viruses enter host cells?

Accepted Answer

Tail fiber injection

Question 9

Retroviruses differ from other RNA viruses because they:

Accepted Answer

Use a DNA intermediary transcribed by reverse transcriptase.

Question 10

Which of the following equations best represents the burst size in the lytic cycle?

Accepted Answer

$$Burst\ Size = \frac{Number\ of\ Virions\ Released}{Number\ of\ Infected\ Cells}$$

Question 11

Which of the following is a correct statement about viral genomes?

Accepted Answer

Viral genomes may be linear, segmented, circular, or single-stranded.

Question 12

A patient is diagnosed with cervical cancer. Which of the following is most likely to have contributed to the development of this cancer?

Accepted Answer

A virus carrying copies of oncogenes as part of its genome.

Question 13

Which of the following best describes the role of capsomeres in viral structure?

Accepted Answer

They are protein subunits that make up the capsid.

Question 14

Which of the following is a consequence of lysogenic conversion in bacteria?

Accepted Answer

The bacterium acquires new phenotypic traits due to phage genes.

Question 15

Which of the following viruses is known to cause Burkitt's lymphoma?

Accepted Answer

Epstein-Barr virus

Question 16

Which of the following best explains why viruses cannot reproduce independently?

Accepted Answer

They lack the necessary enzymes and organelles for replication.

Question 17

Which of the following is true regarding the latency of animal viruses?

Accepted Answer

Incorporation of provirus into host DNA is permanent.

Question 18

Which of the following shapes is NOT a basic type of virion morphology?

Accepted Answer

Spherical

Question 19

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 during release.

Question 20

Which of the following equations correctly represents the calculation of viral genome size compared to cellular genome size?

Accepted Answer

$$Relative\ Size = \frac{Viral\ Genome\ Size}{Cellular\ Genome\ Size}$$

Characterization and Classification of Viruses, Viroids, and Prions

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