Question

What are codominant genes?

Answer 1

Codominant genes:

• Codominant genes are the forms of a gene or alleles of a gene that express themselves fully in presence of each other. Gene is a unit of inheritance that is transferred from one generation to the next.
• As per Mendel’s law of dominance, when two contrasting genes or alleles responsible for a particular characteristic are present together, one of them does not express itself, it is a recessive trait.
• In the codominance, none of the gene forms is suppressed or recessive. Both the alleles express themselves and there is no masking of the expression of either gene form or allele.

Example of codominant genes:

• Gene I is the name of the gene controlling the blood group system in humans.
• This gene possesses three different forms or alleles, I^A, I^B, and I^O.
• Three different alleles are not present together in an individual, and only two alleles are present in one individual.
• I^O is a recessive allele, and the other two alleles are dominant.
• When I^A and I^B are present together, the blood group of the individual is AB because both alleles express themselves.