Question

What is codominance? Explain with an example.

Hint:

Codominance occurs when both alleles contribute equally to the organism's phenotype, as seen in the AB blood group.

Answer 1

Codominance:
Codominance is a genetic phenomenon in which two different alleles of a gene are both expressed in the phenotype of an organism. Unlike incomplete dominance, where one allele partially masks the expression of the other, in codominance, both alleles contribute equally to the organism's traits. This results in a heterozygous individual displaying both traits simultaneously. Example of Codominance:
A well-known example of codominance is the inheritance of the AB blood group in humans. The A and B alleles are codominant, meaning that if an individual inherits both the A allele from one parent and the B allele from the other parent, the resulting phenotype will express both A and B antigens on the surface of the red blood cells. This results in the AB blood type. Genotype and Phenotype:
- Genotype: IAIB (heterozygous)
- Phenotype: AB blood type
In this case, both the A and B alleles are fully expressed, making it a clear example of codominance.