WAEC Biology 2015 Papers

Concept:ABO blood group inheritance uses the alleles $I^A$, $I^B$, and $i$.$I^A$ and $I^B$ are co-dominant, while $i$ is recessive to both.Explanation:In the ABO system, $I^A$ produces antigen A and $I^B$ produces antigen B.The allele $i$ produces no antigen and is recessive.When both $I^A$ and $I^B$ are present, the person has blood group AB.This shows that $I^A$ and $I^B$ are equally expressed, so they are co-dominant.There is no dominance of A over B.Therefore, the statement that A is dominant over B is not true.Answer:A. A is dominant over B