Question 1

Which of the following best describes the structure of a typical enveloped virus?

Accepted Answer

A protein capsid surrounded by a lipid bilayer derived from the host cell membrane

Question 2

Herpesviridae are known for their ability to establish latency. Which of the following best explains viral latency in Herpesviridae?

Accepted Answer

The viral genome persists in host cells without producing infectious virions, often reactivating under stress or immunosuppression

Question 3

Varicella-zoster virus (VZV), a member of the Herpesviridae family, causes which two distinct diseases during a person's lifetime?

Accepted Answer

Chickenpox during primary infection and shingles upon reactivation

Question 4

Which of the following best describes the genome of (+) ssRNA viruses?

Accepted Answer

Single-stranded RNA that can serve directly as mRNA for protein synthesis

Question 5

A patient presents with vesicular lesions along a single dermatome. Which virus is most likely responsible for this presentation?

Accepted Answer

Varicella-zoster virus (VZV) reactivation

Question 6

Which of the following steps is unique to the replication cycle of (+) ssRNA viruses compared to DNA viruses?

Accepted Answer

The viral genome can be immediately translated by host ribosomes upon entry

Question 7

Which of the following best explains why enveloped viruses are generally more sensitive to disinfectants than non-enveloped viruses?

Accepted Answer

Disinfectants disrupt the lipid envelope, which is essential for viral infectivity

Question 8

A laboratory is testing a new antiviral drug that inhibits viral RNA-dependent RNA polymerase. Which class of viruses would be most affected by this drug?

Accepted Answer

(+) ssRNA viruses

Question 9

Which of the following is a common complication of VZV reactivation in elderly patients?

Accepted Answer

Postherpetic neuralgia

Question 10

A (+) ssRNA virus infects a host cell. Which of the following best describes the initial steps of viral replication?

Accepted Answer

The viral RNA is directly translated into viral proteins by host ribosomes

Question 11

Which of the following statements about viral encephalitis caused by (+) ssRNA viruses is correct?

Accepted Answer

It can result from direct viral invasion of the central nervous system, leading to inflammation and neurological symptoms

Question 12

Which of the following best explains why vaccines against VZV are effective in preventing both primary infection and reactivation?

Accepted Answer

They stimulate both humoral and cell-mediated immunity, reducing viral replication and latency

Question 13

A patient with a history of chickenpox develops severe pain and a rash years later. Which process best explains this phenomenon?

Accepted Answer

Reactivation of latent VZV in sensory ganglia

Question 14

Which of the following is a key difference between the replication of (+) ssRNA viruses and (-) ssRNA viruses?

Accepted Answer

(+) ssRNA viruses can be directly translated, while (-) ssRNA viruses require synthesis of a complementary strand before translation

Question 15

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

Accepted Answer

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

Question 16

A researcher is studying a new (+) ssRNA virus. Which laboratory technique would best allow her to detect viral RNA in patient samples?

Accepted Answer

Reverse transcription polymerase chain reaction (RT-PCR)

Question 17

Which of the following best describes the role of viral glycoproteins in the infection process of enveloped viruses?

Accepted Answer

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

Question 18

A patient is diagnosed with encephalitis caused by a (+) ssRNA virus. Which of the following symptoms would most likely be observed?

Accepted Answer

Fever, headache, confusion, and seizures

Question 19

Which of the following is a major reason why antiviral therapy for herpesviruses often fails to completely eliminate the virus from the body?

Accepted Answer

Herpesviruses establish latency in host cells, where they are not actively replicating and thus evade antiviral drugs

Question 20

Which of the following best explains why some (+) ssRNA viruses can cause rapid outbreaks in human populations?

Accepted Answer

Their genomes can be directly translated, allowing for fast replication and high mutation rates

Study Guide: Viruses – Structure, Classification, and Pathogenesis

Guida di studio - Domande di pratica

Study guide - Flashcard