Question

Differentiate between incomplete dominance and co-dominance. Substantiate your answer with one example of each.

Answer 1

Co-dominance	Incomplete dominance
The condition in which two alleles are able to express themselves independently when present together, that is, neither allele is dominant, or even partially dominant, over the other.	The condition in which none of the two contrasting alleles or factors is dominant, and the heterozygote F1 has a phenotype that is intermediate between its the two homozygous parents.
For example, the AB blood group in human beings is characterized by the presence of both antigen A (IA ) and antigen B (IB) on the surface of RBCs. Another example is sickle cell anemia in which the allele for sickle cell hemoglobin HbS is codominant with allele for normal hemoglobin HbA .	For example, in plants like four O’ Clock (Mirabilis jalapa) red and white flowered plants are homozygous for different alleles of a colordetermining gene; and when these are crossed, they produce heterozygotes that have pink flowers. If F1 plants are self-pollinated, the plants of F2 generation are of three types red, pink and white flowered in the ratio of 1:2:1.