Question 3

Remember, because type O blood results from the homozygous recessive genotype (i i ), the only way to produce a type O child is if both parents provide an O allele (i ).

Since the father has blood type A, he must be heterozygous (I^A i ).

Similarly, since the mother has blood type B, she must be heterozygous as well, but with the B and O alleles (I^B i ).

Construct a Punnett square diagram to determine the possible offspring of these two parents:

Based upon these results, we can see that these parents may produce offspring with the following blood type phenotypes: AB, A, B, and O.