$$\text{RNA} \rightarrow \text{DNA} \rightarrow \text{mRNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes the host range of a virus?

Accepted Answer

The number of different species a virus can infect, determined primarily by the presence of specific receptors on host cells.

Question 2

A bacteriophage is a virus that infects which type of organism?

Accepted Answer

Bacteria

Question 3

Which of the following is an example of a zoonotic infection?

Accepted Answer

Rabies transmitted from dogs to humans

Question 4

What is a virion?

Accepted Answer

A complete, infectious virus particle outside a host cell

Question 5

Which structural feature of a virus is responsible for its shape and protection of its genetic material?

Accepted Answer

Capsid

Question 6

Enveloped viruses are often able to evade the immune system more effectively than naked viruses. Which mechanism best explains this?

Accepted Answer

The envelope is derived from the host cell membrane, making the virus less recognizable to the immune system.

Question 7

Which of the following is a common example of a naked virus?

Accepted Answer

Adenovirus

Question 8

The taxonomy of viruses is primarily based on which of the following characteristics?

Accepted Answer

Type of nucleic acid, replication strategy, and morphology

Question 9

Which of the following best describes a prophage?

Accepted Answer

Viral DNA integrated into the bacterial chromosome during the lysogenic cycle

Question 10

During the lytic cycle of a bacteriophage, which phase involves the assembly of new virus particles?

Accepted Answer

Maturation

Question 11

Which of the following best differentiates budding from lysis in animal virus replication?

Accepted Answer

Budding allows the virus to exit the cell without immediately killing it, while lysis results in cell death.

Question 12

Which enzyme is essential for the replication of RNA viruses and is not found in host cells?

Accepted Answer

RNA-dependent RNA polymerase

Question 13

A retrovirus replicates its genome using the following sequence:

Accepted Answer

$$	ext{RNA} ightarrow 	ext{DNA} ightarrow 	ext{mRNA} ightarrow 	ext{Protein}$$

Question 14

Which of the following is a possible outcome when a provirus is formed in a cell?

Accepted Answer

The cell may become oncogenic and develop into a tumor.

Question 15

Which viral proteins are important for the influenza virus to enter and exit host cells?

Accepted Answer

Hemagglutinin and neuraminidase

Question 16

Why do individuals need to get a new flu vaccine every year?

Accepted Answer

The influenza virus undergoes frequent antigenic changes, making previous immunity less effective.

Question 17

Which of the following best describes a prion?

Accepted Answer

An infectious protein that can cause neurodegenerative diseases

Question 18

Which mechanism is currently proposed for how prions cause cellular damage?

Accepted Answer

Prions induce misfolding of normal proteins, leading to aggregation and cell death.

Question 19

Viroids differ from viruses in which of the following ways?

Accepted Answer

Viroids consist only of a short strand of RNA without a protein coat.

Question 20

A patient presents with symptoms of a persistent viral infection. Which of the following best describes this type of infection?

Accepted Answer

The virus remains in the host for a long period, with continuous or intermittent production of virus particles.

Viruses and Prions: Structure, Replication, and Pathogenicity

Study Guide - Practice Questions