4.Principles of Inheritance and Variation
medium

A gene showing codominance has

A

alleles that are recessive to each other

B

both alleles independently expressed in the heterozygote

C

one allele dominant on the other

D

alleles tightly linked on the same chromosome.

(NEET-2015)

Solution

(b) : The phenomenon of expression of both the alleles in a heterozygote is called codominance. The alleles which do not show dominance­recessive relationship and are able to express themselves independently when present together are called codominant alleles. As a result the heterozygous condition has a phenotype different from either of homozygous genotypes, $e.g.$, alleles for blood group $A\ (I^A)$ and for blood group $B\ (I^B)$ are codominant so that when they come together in an individual, they produce blood group $AB$.

Standard 12
Biology

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.