Final answer:
The ABO blood groups in humans are determined by three alleles: IA, IB, and i. The IA and IB alleles are codominant, allowing for both A and B antigens to be expressed in Type AB individuals, whereas they both are dominant over the i allele, which results in Type O blood when in the homozygous form (ii).
Step-by-step explanation:
ABO Blood Group System The ABO blood types in humans are determined by a gene with three alleles: IA, IB, and i. A person can have one of six genotypes: IAIA or IAi (Type A), IBIB or IBi (Type B), IAIB (Type AB), or ii (Type O). Alleles IA and IB are codominant to each other, meaning that both A and B antigens can be fully expressed in Type AB individuals. Both alleles are also dominant over the i allele, which does not produce any antigen and results in Type O blood when homozygous (ii). Therefore, a person with Type O blood cannot have Type A or B blood, as they lack the dominant alleles.Regarding the ABO blood groups in humans, they are expressed as the IA, IB, and i alleles. The IA allele corresponds with the A blood group, the IB allele corresponds with the B blood group, and the i allele corresponds with the O blood group.
When considering mating between a heterozygous Type A parent (IAi) and a heterozygous Type B parent (IBi), there is a possibility for the offspring to have Type AB blood with genotype IAIB, where both the A and B antigens are equally expressed.The ABO blood groups in humans are expressed as the IA, IB, and i alleles. The IA allele encodes the A blood group antigen, IB encodes B, and i encodes O. Both A and B are dominant to O. If a heterozygous blood type A parent (IAi) and a heterozygous blood type B parent (IBi) mate, one quarter of their offspring will have AB blood type (IAIB) in which both antigens are expressed equally. Therefore, the ABO blood groups are an example of