13. Explain the following terms with example
(a) Co-dominance
Codominance-
It refers to the phenomenon of two alleles lacking dominance-recessive relationship and both expressing themselves in the heterozygous condition. In human beings, ABO blood grouping is controlled by gene I. The gene has three alleles IA, IB and i. One person may have any two of these three alleles. Among these alleles, IA, IB are dominant over i. Alleles and . When IA and IB are present together, both express themselves because of co-dominance.