Question 1

Which of the following statements best explains why viruses are not considered living organisms?

Accepted Answer

Viruses are acellular and cannot carry out all life processes independently.

Question 2

A scientist discovers a new infectious agent that consists solely of a naked RNA molecule and infects plants. What is this agent most likely classified as?

Accepted Answer

Viroid

Question 3

Which structural component of a virus provides protection for viral nucleic acids and serves as a means of attachment to host cells?

Accepted Answer

Capsid

Question 4

During viral replication, which step involves the virus commandeering the host cell's transcription and translation machinery to synthesize viral proteins?

Accepted Answer

Biosynthesis

Question 5

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

Accepted Answer

Capsid with a hollow, cylindrical shape

Question 6

A virus with an envelope acquires this structure from which source?

Accepted Answer

Host cell membrane during replication or release

Question 7

Which of the following is a correct sequence of the basic steps in animal virus replication?

Accepted Answer

Attachment → Penetration → Biosynthesis → Assembly and Maturation → Release

Question 8

Which viral disease is characterized by a maculopapular rash and Koplik's spots, and is highly contagious via respiratory droplets?

Accepted Answer

Measles (Morbillivirus)

Question 9

What is the primary function of viral envelope glycoproteins?

Accepted Answer

To mediate host cell recognition and penetration

Question 10

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

Accepted Answer

Virus remains dormant in host cells, sometimes integrating its DNA into the host chromosome, leading to possible reactivation years later.

Question 11

Which of the following is a distinguishing feature of the measles rash?

Accepted Answer

Maculopapular (flat to slightly raised colored bumps)

Question 12

Which of the following viruses is an example of a complex virus with a tail structure used to infect bacteria?

Accepted Answer

Bacteriophage T4

Question 13

Which of the following best describes the biosynthesis step for a negative-sense ssRNA virus?

Accepted Answer

Transcription by RNA-dependent RNA transcriptase to produce mRNA, followed by translation of viral proteins.

Question 14

Which of the following is true regarding prions?

Accepted Answer

They are proteinaceous infectious particles that lack nucleic acids.

Question 15

A patient presents with cold sores on the lips and a history of recurrent outbreaks. Which virus is most likely responsible?

Accepted Answer

Human Herpes Virus 1 (HHV-1)

Question 16

Which of the following is a plausible reason for the resurgence of measles in the USA after its eradication in the early 2000s?

Accepted Answer

Decline in vaccination rates among the population

Question 17

Which equation best represents the Central Dogma of Molecular Biology as it applies to viral biosynthesis in animal cells?

Accepted Answer

$$DNA \rightarrow mRNA \rightarrow Protein$$

Question 18

Which of the following is a correct statement about the release of enveloped viruses from host cells?

Accepted Answer

Enveloped viruses acquire their envelope during budding from the host cell membrane.

Question 19

Which of the following is a plausible consequence of viral fusion protein activity in measles infection?

Accepted Answer

Formation of syncytia, allowing viral particles to pass between host cells and evade antibodies.

Question 20

Which of the following best explains why antibiotics are sometimes used in the treatment of measles?

Accepted Answer

Antibiotics prevent secondary bacterial infections that may develop due to measles.

Viruses: Structure, Replication, and Viral Diseases

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