Question 1

Which of the following best describes a key difference between viruses and bacteria?

Accepted Answer

Viruses lack cellular structure and metabolic machinery, while bacteria are cellular and metabolically active.

Question 2

Which of the following is NOT a criterion used to classify viruses?

Accepted Answer

Presence or absence of a cell wall

Question 3

According to scientific nomenclature, which of the following is a correctly written viral genus name?

Accepted Answer

Herpesvirus

Question 4

Which of the following best describes the lytic cycle of a bacteriophage?

Accepted Answer

The virus immediately replicates and lyses the host cell, releasing new virions.

Question 5

A complex virus is best characterized by which of the following features?

Accepted Answer

A structure with both icosahedral and helical features, often with additional components such as tails or tail fibers

Question 6

Which statement about prions is correct?

Accepted Answer

Prions are infectious proteins that replicate by inducing misfolding of normal host proteins.

Question 7

The viral envelope is primarily derived from which of the following?

Accepted Answer

The host cell's plasma membrane during viral budding

Question 8

Which of the following is a correct sequence of steps for animal virus infection?

Accepted Answer

Attachment, penetration, uncoating, biosynthesis, maturation, release

Question 9

Which property is characteristic of latent viruses?

Accepted Answer

They remain dormant in host cells and can reactivate later.

Question 10

What is the primary function of glycoprotein spikes on the surface of enveloped viruses?

Accepted Answer

To facilitate attachment to specific host cell receptors

Question 11

Which of the following is NOT a common capsid shape found in viruses?

Accepted Answer

Cuboidal

Question 12

Which virus is an example of a latent infection in humans?

Accepted Answer

Herpes simplex virus

Question 13

Which enzyme is unique to retroviruses and is essential for their replication?

Accepted Answer

Reverse transcriptase

Question 14

During bacteriophage multiplication, which step immediately follows attachment?

Accepted Answer

Penetration

Question 15

In RNA viruses, what is the role of the sense (positive) strand?

Accepted Answer

It serves directly as mRNA for protein synthesis.

Question 16

Which of the following best describes the difference between a proto-oncogene and an oncogene?

Accepted Answer

A proto-oncogene is a normal gene that can become an oncogene when mutated or dysregulated.

Question 17

A patient is diagnosed with a chronic viral infection. Which of the following graphs best represents the viral load over time for a chronic infection?

Accepted Answer

A graph showing persistent, low-level viral load over a long period

Question 18

A scientist is studying a new virus with a tail structure and a polyhedral head. Which classification best fits this virus?

Accepted Answer

Complex virus

Question 19

Which of the following best explains how prions differ from viruses?

Accepted Answer

Prions lack nucleic acids, while viruses contain either DNA or RNA.

Question 20

A retrovirus infects a host cell. Which of the following equations best represents the process catalyzed by reverse transcriptase?

Accepted Answer

$$RNA \rightarrow DNA$$

Viruses, Viroids, & Prions: Key Concepts and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard