micro: virology

Question 1

recombination

Answer 1

exchange of genes between 2 chromosomes by crossing over w/in homologous regions

Question 2

reassortment

Answer 2

2 viruses w/segmented genomes (e.g. flu) exchange genetic material (e.g. H1N1)

Question 3

complementation

Answer 3

when 1 virus makes a nonfxnal protein and a coninfecting virus makes a fxnal protein that serves both viruses. e.g. HDV requires HBV to supply HBsAg, which is the envelope protein for HDV.

Question 4

phenotypic mixing

Answer 4

simultaneous infxn w/2 viruses: genome A can be coated w/virus B surface proteins (= pseudovirion). protein coat determines tropism (infectivity) of hybrid virus. progeny look like original A.

Question 5

live vs. killed vaccines

Answer 5

live -> humoral and cell-mediated immunity. no boosters needed. can revert to virulence. smallpox, yellow fever, rotavirus, chickenpox, sabin polio, MMR, flumist. MMR for HIV w/o Sx but otherwise avoid immunocompromised and contacts. killed -> humoral only. rabies, flu shot, salk polio, HAV.

Question 6

RNA viruses mnemonic

Answer 6

Retro Toga party where i drank Flavored Corona and ate Hippy (hepe) California Pickles (picorna)