Incomplete- when heterozygous(CwCr) produces 3rd different phenotype(in this case, pink)
Co-Dominance- When heterozygous displays BOTH homozygous conditions.(blood type iAiB displays BOTH A and B carbohydrates)
Multiple alleles- More than 2 alleles for a single gene(blood has i ia ib)
Polygenic inheritance - When more than one gene contributes to expression of a particular trait.