The inheritance and expression of ABO blood groups in humans are considered to examples of certain genetic phenomena. They are:
The inheritance and expression of ABO blood groups in humans are considered to examples of certain genetic phenomena. They are:
The correct option is D multiple allelism and codominance
Multiple allelism refers to the non-mendelian inheritance where more than two alleles of a gene control the character. Human ABO blood group system is the best example of multiple allelism. The ABO blood groups are controlled by three alleles IA, IB and i, which produce the antigens on the surface of RBC as A, B and O (no antigen) as their phenotypes. The table below shows the various genotypes and phenotypes of the blood groups.
We see that in the heterozygous condition of IA IB both alleles are expressed equally leading to the phenotype of AB. This is an example of codominance. Codominance is a form of inheritance wherein the alleles of a gene pair in a heterozygote are fully expressed.
Epistasis is the phenomenon in which expression of one gene is masked by the expression of another gene which is non-allelic in nature to each other.
Multiple allelism refers to the non-mendelian inheritance where more than two alleles of a gene control the character. Human ABO blood group system is the best example of multiple allelism. The ABO blood groups are controlled by three alleles IA, IB and i, which produce the antigens on the surface of RBC as A, B and O (no antigen) as their phenotypes. The table below shows the various genotypes and phenotypes of the blood groups.
We see that in the heterozygous condition of IA IB both alleles are expressed equally leading to the phenotype of AB. This is an example of codominance. Codominance is a form of inheritance wherein the alleles of a gene pair in a heterozygote are fully expressed.
Epistasis is the phenomenon in which expression of one gene is masked by the expression of another gene which is non-allelic in nature to each other.
