Typically we talk about blood types as B-positive or AB-negative and so forth. The

Question

positive and negative part of the blood type is determined by a completely separate gene (the
Rh locus). The ABO locus and the Rh locus are inherited independently, like pea shape and
pea color. The positive phenotype is dominant to the negative phenotype. A father has
genotype IA IO Rh+Rh– and a mother has genotype IA IB Rh+Rh–.
a. What are the phenotypes of these parents?
b. What is the probability that their only child will have phenotype B-positive?