Explain the following terms with example
Co-dominance
Sometimes both the alleles of genes in a heterozygote lack the dominant and recessive relationship, that is, each allele is capable of some degree of phenotypic expression. In a sense, co-dominance is no dominance at all, the heterozygotes showing the phenotypes of both homozygotes. Hence heterozygote genotype gives rise to a phenotype, distinctly different from either of the homozygous genotypes of parent.
Example: The cote colour of the short horn breed of cattle represents a classical example of co-dominance. When cattle of red coat (CRCR) are crossed with cattle of white coat (CwCw), the F1 heterozygote is found to posses roan coat (CRCw). In roan coat the red and white hair occurs in definite patches but no hair a intermediate colour of red and white. In such a case the F2 phenotypic ratio and genotypic ratio are the same as follows:
