Question

multiple alleles

Accepted Answer

some genes coded for by multiple alleles (more than 2) but organism can only carry 2 versions of the gene (one on each homologous chromosome)
blood group determined by immunoglobulin gene has multiple alleles that code for diff antigens on RBC surface, I^A allele results in prod of antigen A, I^B allele results in prod of antigen B and I^O allele results in prod of neither antigen, I^A and I^B are codominant and I^O recessive, different combos of blood groups are;
A (I^A I^A or I^A I^O)
B (I^B I^B or I^B I^O)
AB (I^A I^B)
O (I^O I^O)

I^A I^B Multiple Alleles Results Prod I^O Gene