Question 1

Which of the following best explains why viruses are generally not considered 'living' organisms?

Accepted Answer

They are unable to reproduce independently outside of a host cell.

Question 2

A scientist is studying a virus that infects only E. coli bacteria. What term best describes this virus?

Accepted Answer

Bacteriophage

Question 3

Which of the following is NOT a component of all virions?

Accepted Answer

Envelope

Question 4

A virus with a helical capsid structure would most likely appear as:

Accepted Answer

A rod-shaped or filamentous particle

Question 5

Which of the following best describes the function of HA and NA spikes on influenza viruses?

Accepted Answer

They facilitate attachment and release from host cells.

Question 6

A patient is infected with a virus that remains dormant in their nerve cells and can reactivate years later. This type of infection is best described as:

Accepted Answer

Latent infection

Question 7

Which of the following statements about viral taxonomy is correct?

Accepted Answer

Viral family names end with the suffix $$-viridae$$

Question 8

Which of the following best defines 'antigenic shift' in influenza viruses?

Accepted Answer

A major change in viral antigens due to genetic reassortment

Question 9

A latex agglutination test is used in a clinical laboratory to detect viral antigens. What is the principle behind this test?

Accepted Answer

Antibodies cause visible clumping of latex beads coated with viral antigens.

Question 10

Which of the following is a correct statement about the use of Koch’s postulates for viral diseases?

Accepted Answer

Koch’s postulates are difficult to apply to viruses because they cannot be grown in pure culture outside of host cells.

Question 11

A virus is described as having a 'narrow host range.' What does this mean?

Accepted Answer

It can infect only specific species or cell types.

Question 12

Which of the following best describes a provirus?

Accepted Answer

Viral DNA integrated into the host genome

Question 13

A researcher is using embryonated eggs to grow a virus for vaccine production. What is a key advantage of this method?

Accepted Answer

It provides a sterile, nutrient-rich environment for viral replication.

Question 14

Which of the following best describes the difference between an enveloped and a naked virus?

Accepted Answer

Enveloped viruses have a lipid membrane surrounding their capsid, while naked viruses do not.

Question 15

A patient is exposed to rabies and receives post exposure prophylaxis. What is the main goal of this intervention?

Accepted Answer

To prevent the virus from establishing infection in the host.

Question 16

Which of the following best describes the process of 'phage conversion'?

Accepted Answer

A bacterium acquires new traits due to the presence of a prophage.

Question 17

Which of the following is a plausible reason why detection and enumeration of viruses is more complicated than for bacteria?

Accepted Answer

Viruses require living host cells for replication.

Question 18

A patient’s blood sample is tested for HIV antibodies, but the result is negative even though the patient was recently exposed. This is most likely due to:

Accepted Answer

The seroconversion window, during which antibodies are not yet detectable.

Question 19

Which of the following best describes the action of nucleoside analogs in antiviral therapy?

Accepted Answer

They mimic natural nucleotides and inhibit viral genome replication.

Question 20

Which of the following is a key function of interferons in the context of viral infections?

Accepted Answer

They induce antiviral states in neighboring cells.

Microbiology Study Guide: Viruses and Prions (Chapter 6)

Guida di studio - Domande di pratica

Study guide - Flashcard