Which of the following conditions represent a case of co-dominant genes.

Options

A. a gene expresses itself, suppressing the phenotypic effect of its alleles
B. genes that are similar in phenotypic effect when present separately, but when together interact to produce a different trait
C. alleles, both of which interact to produce a trait, which may or may not resemble either of the parental types
D. alleles, each of which produces an independent effect in a heterozygous condition

Answer

D

Explanation

Co-dominance is the phenomenon when the two genes neither show dominant-recessive relationship nor show intermediate condition, but both of them express themselves simultaneously. This has been reported in roan character of cattle (i.e., patches of 2 different colours on the skin).