AP-Micro Viral Pathogenesis 2

Question 1

Which viral mechanism allows a pathogen to avoid destruction by cytotoxic T lymphocytes (CTLs)?

Accepted Answer

Downregulating MHC class I expression on infected cells

Answer

Many viruses, including herpesviruses and HIV, downregulate MHC class I to prevent CTLs from recognizing and killing infected cells.

Question 2

What is the role of viral neuraminidase in influenza pathogenesis?

Accepted Answer

Cleaves sialic acid to release new virions from cell surfaces

Answer

Neuraminidase cleaves sialic acid residues on host cell surfaces, releasing newly assembled influenza virions so they can spread to new cells.

Question 3

During viral latency, herpes simplex virus (HSV) genome is maintained in what form within sensory neurons?

Accepted Answer

As a circular episome in the nucleus

Answer

HSV maintains its genome as a circular episomal DNA in the nucleus of sensory neurons during latency, without integrating into host chromosomes.

Question 4

Which term describes the ability of a virus to infect and replicate in multiple different tissue types?

Accepted Answer

Pantropic

Answer

A pantrophic virus has broad tissue tropism, meaning it can infect and replicate in many different cell and tissue types throughout the body.

Question 5

How do non-cytopathic viruses cause host cell damage without directly killing the infected cell?

Accepted Answer

By provoking immune-mediated destruction of infected cells

Answer

Non-cytopathic viruses cause damage primarily through the host immune response, where CTLs and antibodies destroy virally infected cells.

AP Practice Test