(a) Co-dominance: Co-dominance is a genetic scenario in which both alleles in a heterozygous condition are fully expressed, and neither one is dominant or recessive to the other. This means that both alleles are equally dominant, and their traits are equally visible in the phenotype.
An example of co-dominance is the human blood type AB, which is determined by the co-dominant alleles A and B. A person with the AB blood type expresses both A and B antigens on the surface of their red blood cells, indicating that both alleles are expressed equally.
(b) Incomplete dominance: Incomplete dominance is a genetic scenario in which the phenotype of the heterozygous condition is a blend of the phenotypes of the homozygous conditions. In other words, neither allele is fully dominant over the other, and the resulting phenotype is an intermediate between the two.
An example of incomplete dominance is the flower color in snapdragons. The red flower color is caused by the dominant allele (RR), and the white flower color is caused by the recessive allele (rr). When a heterozygous plant (Rr) is produced, the resulting flower color is pink, which is an intermediate between red and white.