Co-dominance: If a plant with yellow coloured flower crosses with a plant of red coloured flower and in F1 generation, all progeny show orange flowers, this is because of co-dominance of both alleles express themselves the phenotype becomes a mix called co-dominance. The human blood group AB is also an example of codominance where both the alleles A and B are equally dominant.
Incomplete dominance: In this, the genes of allelomorphic pairs are not expressed as dominant and recessive but express themselves partially when present together in the hybrid. As a result F1 hybrids show characters intermediate of the parental genes. For example, 4'O clock plant exhibits two types of flowers, red and white.