1. What is the underlying cause of paroxysmal nocturnalhemoglobinuria?
A) Activation of complement by high concentration of oxygen in theblood
B) Increase in hemoglobin concentration during sleep
C) Decreased susceptibility of red blood cells to lysis during sleep
D) Defect in the gene for molecules that attach decay-acceleratingfactor (DAF) and other proteins to the cell membrane

2. Which component of the complement is deficient in hereditaryangioedema?
A) C5a
B) C3a
C) C1 inhibitor
D) C4

3. What is the primary defect in chronic granulomatous disease (CGD)?
A) Deficiency of NADPH oxidase enzyme
B) Decreased respiratory burst in neutrophils
C) Increased susceptibility to low virulence microorganisms
D) Reduced glucose utilization by neutrophils