PCAT Review Questions - Pharmacy College

Answer: C, 50%. There is a two out of four chance that the child will have B blood type.

Key takeaway: Using the Punnett square, it is immediately evident that the child will only have B or AB blood type. The father can donate either an A allele or a B allele, whereas the mother can only donate a B allele. It is shown below that the child is 50% likely to have a B blood type.

A | B
B AB | BB
-------- | -------
B AB | BB