Microorganisms and Disease
Cholera toxin is an A-B type toxin in which the B portions bind to a receptor on a host cell and the A portion enters the cell to cause

ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP
cleavage of rRNA that results in disruption of ribosome function
ADP ribosylation of guanylate cyclase that stimulates production of cGMP
ADP ribosylation of adenylate cyclase that stops production of cAMP

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Microorganisms and Disease
The influenza vaccine is administered each year because

it is a polysaccharide vaccine that does not confer long-term protection
the vaccine is sufficiently toxic to make it necessary to administer only a small amount at any one time
mutations in the viral hemagglutinin may allow the virus to evade the immune response elicited by previous vaccines
None of these

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Microorganisms and Disease
Which of the following characteristic of the Rotavirus was important for the construction of the Rotashield vaccine?

A limited number of capsule types
The ability of the Rotavirus to be transmitted faster
The ability of monkey Rotavirus strains to cause serious illness (diarrhea) in human beings
The possession of a segmented RNA genome

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Microorganisms and Disease
Plastic implants can pose a serious nosocomial infection problem because

phagocytes have trouble engulfing bacteria embedded in a biofilm
phagocytes have trouble moving on the plastic surface
infected implants usually have to be surgically removed
All of these

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