AP BIOLOGY

Detailed explanation-1: -The IA and IB alleles are co-dominant, and the i allele is recessive. The possible human phenotypes for blood group are type A, type B, type AB, and type O.

Detailed explanation-2: -The ABO blood type is inherited in an autosomal codominant fashion. The A and B alleles are codominant, and the O allele is recessive.

Detailed explanation-3: -In blood type, A and B alleles are codominant. Thus, people who get a heterozygous genotype for A and B alleles have blood type AB.

Detailed explanation-4: -Codominance occurs when both alleles show dominance, as in the case of the AB blood type (IA IB) in humans.

Detailed explanation-5: -The ABO gene has three types of alleles: A, B, and O. The first two, A and B, are codominant, in other words, they dominate equally. However, allele O is recessive. The different combinations among these three alleles generate the different blood groups.