Question
Biology Question on Principles of Inheritance and Variation
A gene showing codominance has
alleles that are recessive to each other
both alleles independently expressed in the heterozygote
one allele dominant on the other
alleles tightly linked on the same chromosome.
both alleles independently expressed in the heterozygote
Solution
The phenomenon of expression of both the alleles in a heterozygote is called codominance. The alleles which do not show dominance-recessive 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 (IA) and for blood group B (IB) are codominant so that when they come together in an individual, they produce blood group AB. height - Tall (T) - Dwarf (t)