Questions and answers for exam Preparation

MCQs

Total Questions : 304 | Page 4 of 31 pages

Question 31. The toxins produced by bacteria

kill viruses
encourage bacterial reproduction
interfere with physiological processes in the body
all of the above

Discuss Question

Answer: Option C. -> interfere with physiological processes in the body
Answer: (c).interfere with physiological processes in the body

Question 32. 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 adenylate cyclase that stops production of cAMP
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

Discuss Question

Answer: Option B. -> ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP
Answer: (b).ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP

Question 33. Pseudomembraneous colitis is

precipitated by the use of certain antibiotics
caused by a gram-positive bacterium
caused by a spore-forming bacterium
all of the above

Discuss Question

Answer: Option D. -> all of the above
Answer: (d).all of the above

Question 34. Both Mycobacterium tuberculosis and Streptococcus pneumoniae

are acquired by inhalation
have cell walls that contain a high content of mycolic acids
have polysaccharide capsules
stay in the lung and rarely, if ever, enter the bloodstream

Discuss Question

Answer: Option A. -> are acquired by inhalation
Answer: (a).are acquired by inhalation

Question 35. Mucus helps in protecting against pathogens by

lowering the pH
facilitating the growth of normal flora
blocking access and attachment of pathogens to mucosal surfaces
sequestering Iron

Discuss Question

Answer: Option C. -> blocking access and attachment of pathogens to mucosal surfaces
Answer: (c).blocking access and attachment of pathogens to mucosal surfaces

Question 36. Which of the following is common in the disease caused by Coryne-bacterium diphtheriae and Bacillus anthracis?

Both organisms are gram-positive spore formers
Diphtheria toxin and edema toxin are ADP ribosylating toxins
The most serious disease symptoms are the direct result of toxin action
Both organisms cause skin and respiratory tract infections

Discuss Question

Answer: Option C. -> The most serious disease symptoms are the direct result of toxin action
Answer: (c).The most serious disease symptoms are the direct result of toxin action

Question 37. Each of the 3 virulence factors of Bacillus anthracis i.e. the capsule, edema toxin and lethal toxin can affect the activity of