Question

Differentiate between Dominance, Incomplete dominance and Co-dominance with the help of a suitable example of each.

Answer 1

• Dominance: In this pattern, one allele shows its effect in a heterozygous condition while the other allele is masked. For example, in the ABO blood group system, the inheritance of A, B, and O follows this rule where the dominant allele expresses itself over the recessive one.
• Codominance: In codominance, both alleles of a gene are expressed equally in a heterozygous individual. For example, in the AB blood group, both IA and IB alleles are expressed together.
• Incomplete dominance: In this case, neither allele is completely dominant over the other in a heterozygous condition, resulting in an intermediate phenotype. An example is the flower colour in snapdragon (Antirrhinum), where the hybrid shows a blended trait.