The A and B antigens in humans may be found in water-soluble form in secretions, including saliva, of some individuals (Se/Se and Se/se) but not in others (se/se). The population thus contains "secretors" and "nonsecretors."
(a) Determine the proportion of various phenotypes (blood type and ability to secrete) in matings between individuals that are blood type AB and type O, both of whom are Se/se.
(b) How will the results of such matings change if both parents are heterozygous for the gene controlling the synthesis of the H substance (Hh)?