Human Heredity 11th Edition by Michael Cummings

Exercise 41

In homozygotes, the recessive allele h prevents the A and B antigens from being placed on the surface of cells in individuals carrying either the I A or I B allele (or both alleles). The normal H allele allows these antigens to be placed on cell surfaces.
A) Predict all possible blood-type phenotypes and their ratios in a cross between HhAB 3 HhAB individuals.
B) Among those individuals with type O blood, what genotypes are present, and in what ratios?