Question

q5. what is incomplete dominance? how would mendels conclusions have differed if he had worked with plants whose alleles were incomplete dominant. app /6

Explanation:

Incomplete dominance is a genetic phenomenon where neither allele is completely dominant over the other. Instead, the heterozygous phenotype is an intermediate blend of the two homozygous phenotypes. For example, in snapdragons, a red - flowered plant (RR) and a white - flowered plant (rr) produce pink - flowered (Rr) offspring.

If Mendel had worked with plants showing incomplete dominance:

• His law of dominance (where one allele masks the other) would not be as straightforward. Instead of clear - cut dominant and recessive phenotypes in the \(F_1\) generation (like in his pea plant experiments where \(F_1\) showed the dominant trait), he would have observed intermediate phenotypes.
• When analyzing the \(F_2\) generation, the phenotypic ratio would be \(1:2:1\) (e.g., red:pink:white in the snapdragon example) instead of the \(3:1\) ratio he observed in his pea plant experiments with complete dominance. This would have made it more difficult to formulate the simple laws of inheritance he did, as the clear - cut separation of dominant and recessive traits would be less obvious.

Answer:

Incomplete dominance is when neither allele is fully dominant, and heterozygotes show an intermediate phenotype. If Mendel used such plants, \(F_1\) would have intermediate traits (not just dominant), and \(F_2\) would have a \(1:2:1\) phenotypic ratio (not \(3:1\)), complicating his law - formulation.