Multiple choice

If the father of a developing embryo is Rh positive and the mother is Rh negative, what are the chances that there will be a mother-fetus incompatibility problem? (Assuming that the lady has already had a son and 2 daughters and that there has been no medical treatment to anticipate this problem)

  1. 100%

  2. At least 50%

  3. Less than 50%

  4. 0%

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the father is homozygous dominant (DD) the chances of the fetus being Rh positive and an incompatibility problem occurring will be 100%. If the father is heterozygous (Dd), the chances are 50%. There will be no problem if the fetus is Rh negative.