What are multiple alleles Describe multiple alleles with the help of ABO blood groups in man.

Explanation

Generally a gene has two alter.. forms call. alleM. Someetimes a gene m, have more than two These are referred to as multiple alleles. When more than two al.. exist in a population of a specific Organism, the phenomenon is cell. multiple alielism. Multiple alleles cannm be observed in the genotype of a diploidInthvidual, but cart be observed in a population.
The number of genotypes that can occur for multiple alleles is given by the expression where n=number of alleles.
The.ABO blood group system was proposed by Kari Landsteiner.. The blood groups A, B.. and 0 types are characterised by the presence or absence of antigens on the surface of RBC. Blood type .A. person have antigen A on their RBCs and anti-B antibodies in the plasma Blood type B! person have antigen a On their RBCs and anti-A antibodies in the plasma Blood type...person have antigens A and B on the RBCs and no antibodies in the plasma. Blood type O person have no antigens on the. RBCs and both anti-A, and anti-B antibodies are present in the plasma.

Bernstein discovered that these phenotypes were inherited by the interaction of the three autosomal alleles of teh gene named T located on chromosomes 9. `I^A I^B and I^O` are the three alleles of the gene I. The alleles `I^A and I^B` are responsible for the production of the respective antigens A and B. The allele `I^O` does not produce any antigen. The alleles `I^A and I^B` are dominant to the allele `I^O` but co-dominant to each other `(I^A=I^B gt I^O)`
A child receives one of the three alleles from each parent, giving rise to six possible. genotypes and four possible blood types, The genotypes are `I^A I^A, I^A I^O , I^B I^B, I^B I^O, I^A I^B ,I^O I^O`. The phenotypic expression of `I^A I^A and I^A I^O`. are A type blood. the phenotypic expression of `I^B. I^B and I^B I^O` are B type blood. and that of `I^A I^B` , the AB blood type. The phenotype `I^O I^O` (ii) is O type blood.