What is the probability of a type A mother and a type AB father having a type O child?

Answer 1

There is a zero chance that any of the offspring would be blood type O, or (ii,ii).

-The father provides either an I_A or an I_B while the mother provides I_A or an ii.

-Both parents would need to have a recessive allele, ii, in order to have blood type O offspring with both ii,ii alleles.