Question

the blood type considered the universal recipient is type *
o+
ab-
o-
ab+
the second heart sound is caused by the closing of the _____ valve(s). *
mitral
semilunar
tricuspid
both mitral and tricuspid
which combination of parents might have a child with erythroblastosis fetalis?
both parents are rh positive.
both parents are rh negative.
the mother is rh positive; the father is rh negative
the mother is rh negative, the father is rh positive

Explanation:

1. For the universal recipient blood type: AB+ blood has no anti-A, anti-B, or anti-Rh antibodies in plasma, so it can receive all blood types.
2. For the second heart sound: The second heart sound (S2) occurs when the semilunar (aortic and pulmonary) valves close at the end of ventricular systole.
3. For erythroblastosis fetalis: This condition happens when an Rh-negative mother is sensitized to Rh-positive fetal blood (from an Rh-positive father), producing antibodies that attack subsequent Rh-positive fetuses.

Answer:

1. AB+
2. semilunar
3. The mother is Rh negative; the father is Rh positive