AP BIOLOGY

Detailed explanation-1: -Instead, people who get two different alleles, called heterozygotes, express both alleles equally. 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-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: -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.

Detailed explanation-4: -One parent with A and another with B can produce a child with A, B, AB or O blood types. If one parent has A and another has AB, they can either produce a child with A, B or AB blood types.

Detailed explanation-5: -The ABO blood group antigens are encoded by one genetic locus, the ABO locus, which has three alternative (allelic) forms-A, B, and O. A child receives one of the three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes).