6. The toxins produced by bacteria
A. kill viruses
B. encourage bacterial reproduction
C. interfere with physiological processes in the body
D. all of the above
7. Pseudomembranous colitis is
A. precipitated by the use of certain antibiotics
B. caused by a gram-positive bacterium
C. caused by a spore-forming bacterium
D. all of the above
8. Both Mycobacterium tuberculosis and Streptococcus pneumoniae
A. are acquired by inhalation
B. have cell walls that contain a high content of mycolic acids
C. have polysaccharide capsules
D. stay in the lung and rarely if ever, enter the bloodstream
9. 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
A. ADP ribosylation of adenylate cyclase that stops production of cAMP
B. ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP
C. cleavage of rRNA that results in disruption of ribosome function
D. ADP ribosylation of guanylate cyclase that stimulates the production of cGMP
10. Mucus helps in protecting against pathogens by
A. lowering the pH
B. facilitating the growth of normal flora
C. blocking access and attachment of pathogens to mucosal surfaces
D. sequestering Iron