Question

Explain the following term with an example.

Co-dominance

Answer 1

Codominance (1 : 2 : 1) refers to the phenomenon in which two alleles (different forms of a Mendelian component present on the same gene locus on homologous chromosomes) lack a dominant-recessive link and can express themselves independently when present together.

Example – AB blood group: Alleles for blood groups A (I^A) and B (I^B) are codominant; therefore, they form blood group AB when they come together in a person. It can be identified by the presence of antigens A (from I^A) and B (from I^B) on the surface of erythrocytes.