Question 1

Which of the following statements best explains why viruses are considered obligate intracellular parasites?

Accepted Answer

They require a living host cell to carry out metabolic processes and replication.

Question 2

A scientist isolates a virus with a rod-shaped capsid, an RNA genome, and no envelope. Based on its structure, which virus is it most similar to?

Accepted Answer

Tobacco mosaic virus

Question 3

Which of the following best describes the function of glycoprotein spikes on enveloped viruses?

Accepted Answer

They facilitate attachment to specific host cell receptors.

Question 4

Which of the following is NOT a characteristic of viruses?

Accepted Answer

They possess both DNA and RNA as genetic material.

Question 5

A virus is classified as a Group IV virus in the Baltimore classification. Which of the following best describes its genome and replication strategy?

Accepted Answer

Single-stranded positive-sense RNA, genome can serve directly as mRNA

Question 6

Which of the following is a correct statement about the viral envelope?

Accepted Answer

It is a lipid membrane derived from the host cell during viral budding.

Question 7

Which of the following best describes the role of the capsid in a virion?

Accepted Answer

It protects the viral genome and aids in delivery into host cells.

Question 8

A patient is infected with a virus that mutates rapidly, leading to drug resistance. Which viral property is most responsible for this phenomenon?

Accepted Answer

High mutation rate during replication

Question 9

Which of the following is the correct hierarchical order for virus taxonomy, from highest to lowest rank?

Accepted Answer

Order, Family, Genus, Species

Question 10

Which of the following statements about the virome is correct?

Accepted Answer

The virome includes all viruses present in a particular environment, such as the human body or aquatic systems.

Question 11

Which of the following viruses was both the first virus discovered and the first visualized by electron microscopy?

Accepted Answer

Tobacco mosaic virus

Question 12

Which of the following best explains why enveloped viruses are generally less stable outside a host cell compared to non-enveloped viruses?

Accepted Answer

Their lipid envelope is sensitive to desiccation, detergents, and heat.

Question 13

A virus with a segmented, double-stranded RNA genome is most likely classified in which Baltimore group?

Accepted Answer

Group III

Question 14

Which of the following is a real-world application of viruses in medicine?

Accepted Answer

Using bacteriophages to treat bacterial infections resistant to antibiotics

Question 15

Which of the following best describes a virophage?

Accepted Answer

A subviral agent that infects giant viruses within a host cell

Question 16

Which of the following is the correct binomial species name for Zika virus according to current ICTV nomenclature?

Accepted Answer

Orthoflavivirus zikaense

Question 17

A newly discovered virus has a helical capsid, RNA genome, and an outer lipid layer with spike proteins. Predict its likely mode of entry into host cells and discuss how its architecture might influence vaccine development.

Accepted Answer

It likely enters by direct fusion with the host cell membrane; spike proteins are key antigens for vaccine targeting.

Question 18

Which of the following best describes the Baltimore classification system?

Accepted Answer

It classifies viruses based on their genetic material and the pathway to mRNA synthesis.

Question 19

Which of the following is a function of the capsid in a virus?

Accepted Answer

It provides structural stability and protects the viral genome.

Question 20

Which of the following statements about the human virome is TRUE?

Accepted Answer

The human virome can influence both health and disease states.

Introduction to Virology: Structure, Classification, and Importance of Viruses

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