Q: Which of the following equations best represents the burst size in a lytic viral replication cycle?

$$\text{Burst size} = \frac{\text{Number of virions released}}{\text{Number of infected cells}}$$

Question 1

Which of the following statements best describes the extracellular state of a virus?

Accepted Answer

It is called a virion and consists of a nucleic acid surrounded by a protein coat, sometimes with a phospholipid envelope.

Question 2

A virus with a genome composed of single-stranded RNA that acts directly as mRNA upon infection is classified as which of the following?

Accepted Answer

A positive-sense ssRNA virus

Question 3

Which of the following best explains why most viruses are host-specific?

Accepted Answer

Viral surface proteins have affinity for complementary proteins on the host cell surface.

Question 4

During the lytic replication cycle of a bacteriophage, what is the correct order of events?

Accepted Answer

Attachment, Entry, Synthesis, Assembly, Release

Question 5

Which of the following is a unique feature of enveloped viruses compared to naked viruses?

Accepted Answer

They acquire a phospholipid bilayer from the host cell during replication or release.

Question 6

A scientist is culturing a virus that requires a host cell for replication. Which of the following methods would be most appropriate for culturing this virus?

Accepted Answer

Inoculation into embryonated chicken eggs

Question 7

Which of the following best describes the process of lysogenic conversion?

Accepted Answer

A bacteriophage integrates its genome into the host chromosome, potentially altering the host phenotype.

Question 8

Which of the following is a characteristic of prion diseases?

Accepted Answer

They cause fatal neurological degeneration and spongiform changes in brain tissue.

Question 9

Which of the following equations best represents the burst size in a lytic viral replication cycle?

Accepted Answer

$$	ext{Burst size} = \frac{	ext{Number of virions released}}{	ext{Number of infected cells}}$$

Question 10

Which of the following is a correct statement about the replication of animal viruses?

Accepted Answer

DNA viruses often enter the nucleus, while RNA viruses usually replicate in the cytoplasm.

Question 11

A patient is diagnosed with a cancer that is linked to a viral infection. Which of the following mechanisms best explains how a virus can induce cancer?

Accepted Answer

The virus inserts into the host's repressor gene, preventing the production of proteins that inhibit cell division.

Question 12

Which of the following best describes a viroid?

Accepted Answer

An extremely small, circular piece of RNA that is infectious and pathogenic in plants.

Question 13

Which of the following laboratory observations would best indicate the presence of a lytic bacteriophage in a bacterial culture?

Accepted Answer

Clear plaques forming in a lawn of bacterial growth on an agar plate.

Question 14

Which of the following is a plausible reason why enveloped viruses are generally more sensitive to disinfectants than naked viruses?

Accepted Answer

Disinfectants disrupt the phospholipid bilayer of the envelope, inactivating the virus.

Question 15

Which of the following best explains why prion diseases are difficult to eliminate from contaminated surgical instruments?

Accepted Answer

Prions are only destroyed by incineration or autoclaving in 1 N NaOH.

Question 16

A virus is found to have a segmented, double-stranded RNA genome. Which family is it most likely to belong to?

Accepted Answer

Reoviridae

Question 17

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

Accepted Answer

They facilitate attachment and recognition of host cells.

Question 18

Which of the following is a key difference between the lytic and lysogenic cycles of bacteriophage replication?

Accepted Answer

The lysogenic cycle involves integration of the phage genome into the host chromosome as a prophage.

Question 19

Which of the following best explains why viruses are not considered living organisms by some scientists?

Accepted Answer

They cannot carry out metabolic pathways or reproduce independently.

Viruses, Viroids, and Prions: Structure, Classification, and Replication

Study Guide - Practice Questions

Study Guide - Flashcards