Question

The gene I that controls the ABO blood grouping in human beings, has three alleles, IA, IB and i.
(a) How many different genotypes are likely to be present in the human population?
(b) Also, how many phenotypes are possibly present? [CBSE Sample Paper 2016]

Answer 1

In ABO blood group system, inheritance of grouping is controlled by a single autosomal gene on chomosome 9 with three major alleles A, B and O (IA,IB and IO). The ABO blood group system has at least 6 genotypes.