ABO blood grouping in humans is an example of
A.Polymeric inheritance - Inheritance is controlled by two or more genes in which the dominant alleles have cumulative effect, with each dominant allele expressing a part of functional polypeptide and full trait is shown when all the dominant alleles are present, is called Polygenic or Quantitative inheritance. Eg:kernel colour of Wheat.
B.Multiple allelism - Presence of more than two alleles for a gene is called Multiple alleles. These are present on the same locus of homologous chromosomes. eg:ABO blood group.
C.Epistasis - A gene which masks the action of another gene is termed as epistasis. The gene is called epistatic gene and the gene whose effect is masked is termed as hypostatic gene. eg:Body colour of Mice.
D.Pleiotropism - The ability of a gene to have a multiple phenotypic effects is known as pleiotrophy and the gene is called Pleiotropic gene and the inheritance is called Pleiotropic inheritance. Eg:Sickle cell anaemia.
E.Incomplete dominance - Appearance of new phenotypes or intermediate phenotypes, other than parental phenotypes in progeny is incomplete dominance. eg:Flower colour of Snapdragon.
So, the correct option is ‘Multiple allelism’.