Question 1

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

Accepted Answer

Viruses contain either DNA or RNA, but never both.

Question 2

A virus is able to infect only certain types of cells within a host. What is the primary reason for this specificity?

Accepted Answer

The affinity of viral surface molecules for complementary structures on the host cell surface.

Question 3

Which of the following is NOT a characteristic of viroids?

Accepted Answer

Viroids infect animal cells and cause neurological diseases.

Question 4

Which step in the lytic replication cycle of bacteriophages involves the destruction of the host cell?

Accepted Answer

Release

Question 5

What distinguishes the replication of animal viruses from bacteriophages?

Accepted Answer

Animal viruses may have an envelope and infect eukaryotic cells lacking a cell wall.

Question 6

Which of the following is a correct statement about prions?

Accepted Answer

Prions are infectious proteins that cause fatal neurological degeneration.

Question 7

A virus with a helical capsid morphology would most likely appear as:

Accepted Answer

A rod-shaped structure.

Question 8

Which of the following equations best represents the exponential increase in viral particles during the lytic cycle?

Accepted Answer

$$N_t = N_0$ e$$^{rt}$$

Question 9

Which factor is NOT involved in the activation of oncogenes by viruses?

Accepted Answer

Antibiotics

Question 10

Which of the following best explains why prion diseases are difficult to control?

Accepted Answer

Prions are only destroyed by incineration, not by cooking or sterilization.

Question 11

A plant shows stunted growth and abnormal leaf morphology. Which infectious agent is most likely responsible?

Accepted Answer

A viroid

Question 12

Which of the following is a function of viral glycoprotein spikes?

Accepted Answer

Attachment to host cell receptors

Question 13

During lysogenic replication, what happens to the viral genome?

Accepted Answer

It integrates into the host cell genome and remains dormant.

Question 14

Which of the following is NOT a characteristic of viral envelopes?

Accepted Answer

They protect the viral genome from UV radiation.

Question 15

Which of the following diseases is associated with prions?

Accepted Answer

Creutzfeldt-Jakob Disease (CJD)

Question 16

Which of the following best describes the process of viral budding?

Accepted Answer

The virus acquires an envelope from the host cell membrane during release.

Question 17

Which equation represents the probability $$P of a $$virus successfully attaching to a host cell, given $$n$$ available receptors and $$m$$ viral particles?

Accepted Answer

$$P = 1 - e$$^{-nm}$$

Question 18

Which of the following is a plausible consequence of viral infection leading to cancer?

Accepted Answer

Activation of oncogenes and inhibition of tumor suppressors

Question 19

Which of the following is NOT a typical host for viruses?

Accepted Answer

Minerals

Question 20

Which of the following best describes the structure of a complex virus?

Accepted Answer

A polyhedral head with a tail and tail fibers

Classification and Characteristics of Viruses, Viroids, and Prions

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