Which of the following blood groups may be present in the children of a couple having blood groups A and B respectively? (a)A and B only (b)A B and AB (c)A B AB and O (d)A B only
Option C) A heterozygous woman with type A blood and a heterozygous man with type B blood have, as you figured with your Punnet square, a 25% chance with each child that the child will have blood group O, 25% chance for blood group A, 25% chance for blood group B, and 25% chance for blood group AB. The same is true for the reciprocal cross: a heterozygous woman with type B blood and a heterozygous man with type A blood. In such a family, the existence of a child with blood group O is evidence that both parents are heterozygous.
