Question

What type of genetic inheritance determines the ABO blood group system? What are the relations of dominance among the involved alleles?

Answer 1

ABO blood groups are inherited both from parents. The ABO blood type is controlled by a single gene ( ABO gene) with three types of alleles inferred from classical genetics. The gene encodes an enzyme that modifies the carbohydrate content of the red blood cell antigens. The gene is located on the long arm of the ninth chromosome. The A and B are the dominant alleles. So if u have A0 or AA ur blood group is A, the same for B. To be 0 you have to be 00, because it's the recessive allele. And because A and B are both dominant, if you have both your blood group is AB.

The inheritance of the ABO blood system is a form of multiple alleles inheritance. There are three alleles involved, IA, IB and i which combine in pairs to form the genotypes. Concerning dominance, the allele i is recessive in relation to the alleles IA and IB. Between IA and IB, however, a lack of dominance is established and the heterozygous pair (IAIB) has its own distinct phenotype.