Question

Explain the following terms with example
(a) Co-dominance
(b) Incomplete dominance

Answer 1

Co-dominance: When both recessive and dominant traits are expressed in a heterozygous genotype. This means that none of the factors is recessive but both can express themselves irrespective of their presence in homozygous or heterozygous condition. For example, $I^A$ and $I^B$ alleles of I gene of ABO blood group.

Incomplete dominance: When none of the factors of a gene is dominant, the phenotype of a heterozygous dominant individual is a blend of dominant and recessive traits. For example, flower colour in Mirabilis jalapa.