Question 1

Which of the following best defines a virus?

Accepted Answer

A non-cellular infectious agent composed of genetic material surrounded by a protein coat

Question 2

Which structure is NOT commonly associated with viruses?

Accepted Answer

Ribosome

Question 3

During the bacteriophage lytic replication cycle, which step immediately follows the injection of viral DNA into the host cell?

Accepted Answer

Biosynthesis of viral components

Question 4

Which of the following best describes the difference between the lytic cycle and lysogeny in bacteriophage replication?

Accepted Answer

Lytic cycle results in immediate destruction of the host cell, while lysogeny involves integration of viral DNA into the host genome without immediate lysis.

Question 5

Phage conversion is best illustrated by which scenario?

Accepted Answer

A bacterium gains the ability to produce a toxin after lysogenic infection by a bacteriophage.

Question 6

Why is bacteriophage important in the progression of Scarlet Fever?

Accepted Answer

The bacteriophage introduces genes encoding erythrogenic toxin into Streptococcus pyogenes, enabling toxin production.

Question 7

Which method of culturing viruses is most suitable for studying the replication of influenza virus?

Accepted Answer

Embryonated eggs

Question 8

Primary cells, immortalized cells, and transformed cells differ in which key aspect?

Accepted Answer

Primary cells have limited lifespan, immortalized cells can divide indefinitely, and transformed cells exhibit uncontrolled growth and loss of contact inhibition.

Question 9

Which statement about oncogenes is correct?

Accepted Answer

Oncogenes are genes that can transform a normal cell into a cancerous cell.

Question 10

Contact inhibition is best described as:

Accepted Answer

The ability of cells to stop dividing when they touch neighboring cells.

Question 11

Which dsDNA virus family is enveloped, replicates in the nucleus, and has transforming members?

Accepted Answer

Herpesviridae

Question 12

Which virus is associated with both latent infection and the development of cancer?

Accepted Answer

Epstein Barr Virus (EBV)

Question 13

Latency in Herpes viruses refers to:

Accepted Answer

The state in which viral DNA remains dormant in host cells without producing new virions.

Question 14

How can chicken pox lead to shingles later in life?

Accepted Answer

The Varicella Zoster Virus remains latent in nerve cells and can reactivate as shingles.

Question 15

Viremia is defined as:

Accepted Answer

The presence of viruses in the bloodstream.

Question 16

Which of the following is a positive strand single strand RNA virus?

Accepted Answer

Poliovirus (Picornaviridae)

Question 17

Which ssRNA virus family is enveloped, has a segmented genome, and is a negative strand virus?

Accepted Answer

Orthomyxoviridae

Question 18

In the replication cycle of a retrovirus, which enzyme is responsible for synthesizing DNA from an RNA template?

Accepted Answer

Reverse transcriptase

Question 19

Which equation best represents the action of reverse transcriptase in retrovirus replication?

Accepted Answer

$$	ext{RNA} \xrightarrow{	ext{Reverse Transcriptase}} 	ext{DNA}$$

Question 20

Which statement correctly compares provirus and prophage?

Accepted Answer

A provirus is viral DNA integrated into a eukaryotic host genome, while a prophage is viral DNA integrated into a bacterial genome.

Question 21

Which retrovirus is associated with cell transformation and cancer development?

Accepted Answer

HTLV

Question 22

Which of the following best defines a prion?

Accepted Answer

A misfolded protein that can induce abnormal folding of other proteins

Microbiology Study Guide: Viruses (Chapter 13)

Study Guide - Practice Questions

Study Guide - Flashcards