Viruses

Question 1

The envelopes of viruses contain what?

Answer 1

Lipid bilayer and surface protein

Question 2

What is recombination?

Answer 2

Exchange of genes between 2 chromosomes by crossing over within regions of significant base sequence homology

Question 3

What is reassortment?

Answer 3

When viruses with segmented genomes exchange segments. Cause of worldwide influenza pandemics.

Question 4

What is complementation?

Answer 4

When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The nonmutated virus “complements” the mutated one by making a functional protein that serves both viruses.

Question 5

What is phenotypic mixing?

Answer 5

Occurs with simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) with surface proteins of virus B. Type B protein coat determines the tropism (infectivity) of the hybrid virus. However, the progeny from this infection have a type A coat that is encoded by its type A genetic material.

Question 6

All DNA viruses except which are dsDNA?

Answer 6

Parvoviridae

Question 7

All DNA viruses are linear except which?

Answer 7

Papilloma-, polyoma-, and hepadnaviruses (circular)

Question 8

All RNA viruses except which are ssRNA?

Answer 8

Reoviridae

Question 9

What is the mnemonic for positive-stranded RNA viruses?

Answer 9

I went to a retro (retrovirus) toga (togavirus) party where I drank flavored (flavivirus) Corona (coronavirus) and ate hippy (hepevirus) California (calicivirus) pickles (picornavirus)

Question 10

Most enveloped viruses acquire their envelopes from plasma membrane when exiting the cell except for which one?

Answer 10

Herpesviruses which acquire envelopes from nuclear membrane

Question 11

HSV-1 is dormant where?

Answer 11

Trigeminal ganglia

Question 12

What is the treatment of HSV-1?

Answer 12

Valcyclovir

Question 13

What are all the disease manifestations of HSV-1?

Answer 13

Gingivostomatitis, keratoconjunctivitis, temporal lobe encephalitis, herpes labialis, and herpetic Whitlow

Question 14

What are Cowdry bodies?

Answer 14

Host cells of HSV-1 and HSV-2 with big red intranuclear eosinophilic inclusion bodies that look like targets

Question 15

What are all the disease manifestations of HSV-2?

Answer 15

Herpes genitalis, aseptic meningitis, and neonatal herpes

Question 16

HSV-2 is dormant where?

Answer 16

Sacral ganglia

Question 17

Chicken pox in adults can lead to what complications?

Answer 17

Pneumonia and encephalitis

Question 18

Where does VZV remain latent?

Answer 18

Dorsal root ganglia (or trigeminal ganglia)

Question 19

What is the treatment for VZV?

Answer 19

Acyclovir

Question 20

Describe congenital varicella syndrome

Answer 20

ToRCHES infection; Limb hypoplasia, cutaneous scarring in a dermatomal pattern, and blindness

Question 21

What kind of vaccine is the rotavirus vaccine?

Answer 21

Live-attenuated, oral

Question 22

What are the three enteroviruses?

Answer 22

Echovirus, Poliovirus, Coxsackievirus

Question 23

Rhinovirus attaches to cells via what?

Answer 23

ICAM-1

Question 24

Which virus causes SARS and MERS?

Answer 24

Coronavirus