<em>Codominance is a genetic situation in which the two alleles representing a particular gene exert equal effects on each other when in heterozygous condition. Both alleles are phenotypically expressed in the heterozygous organism.</em>
In this case, the black and brown coat color were expressed in the resulting offspring of the cross, a clear indication of codominance.
Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed.
