Co-dominance vs Incomplete Dominance — NEET Biology

Co-dominance occurs when both alleles are equally expressed in the heterozygote (e.g., AB blood type shows both A and B antigens), while incomplete dominance produces an intermediate phenotype (e.g., red × white flowers = pink). Students often confuse these by thinking incomplete dominance means both traits show equally—it actually means a *blend* or intermediate expression. The key distinction: co-dominance = both traits visible separately; incomplete dominance = new intermediate trait. NTA tests this by giving flower colors, blood groups, or cattle coat colors and asking students to identify which pattern is shown. Remember that co-dominance doesn't create a new phenotype, but incomplete dominance does.