Write a short note on multiple alleles considering the example of human blood group.

Explanation

1. ABO blood groups in human beings are determined genetically due to multiple alleles of gene I.
2. These multiple alleses are `I^(A),I^(B)` and `i`.
3. `I^(A)` and `I^(B)` are codominant alleles whilke i is recessive to both `I^(A)` and `I^(B)`.
4. The allele `I^(A)` and `I^(B)` produce different forms of antigen while allele il does not produce any antigen.