Question

Why is human abo blood group gene considered a good example of multiple alleles?

Answer 1

Human ABO blood grouping is considered to be the best example of multiple alles because the gene I (gene that regulates the blood group) has 3 allelic forms , Ia ,Ib and i .
The blood group of the person will depend on what allele of the gene he carries . for example : person having ii would have group O and another person having Ia i would have blood group A .