Final answer:
If an Igh(a/a) mother and an Igh(b/b) father reproduce, their offspring will express Igh(a/b), resulting in a heterozygous genotype.
Step-by-step explanation:
When considering offspring genetics, if you have an Igh(a/a) mother and an Igh(b/b) father, the kind of Igh the offspring will express is Igh(a/b). This is because each parent can only pass on one allele from their pair to their offspring. The result is a combination of one allele from each parent, making the offspring heterozygous for that gene.
The ABO blood group is also a great example of this concept, with the IA allele encoding the A blood group antigen, IB encoding B, and i encoding O. Since both A and B are dominant to O, in cases where heterozygous blood type A parent (A) and heterozygous blood type B parent (B) mate, the offspring have a possibility of expressing an AB blood type, which demonstrates codominance and is an example of inheritance that involves multiple alleles.