Final answer:
The possible blood type phenotypes of children from parents with genotypes IAi and IBi are A, B, AB, or O, due to the codominance of IA and IB alleles and their dominance over the i allele.
Step-by-step explanation:
Possible Phenotypes of Children from Parents with ABO Genotypes IAi and IBi
The question concerns the phenotypes of offspring when one parent has the genotype IAi (blood type A) and the other has the genotype IBi (blood type B). The possible phenotypes for the children would be blood types A (IAi), B (IBi), AB (IAIB), or O (ii). This is due to the fact that both the IA and IB alleles are codominant, expressing both antigens, and are dominant over the i allele. Children inherit one allele from each parent, resulting in four possible combinations in this case.
In the ABO blood type system, these combinations lead to the following potential phenotypes: blood type A can result from genotypes IAIA or IAi, blood type B from IBIB or IBi, blood type AB from IAIB, and blood type O from ii. As the IA and IB alleles are codominant, if both alleles are present (IAIB), both A and B antigens will be expressed equally, leading to blood type AB.