Question

explain why polygenic traits are expressed through quantitative variation, using skin color as an example.

Explanation:

Polygenic traits are controlled by multiple genes. In the case of skin - color, different combinations and amounts of alleles from multiple gene loci contribute to a wide range of phenotypes, resulting in quantitative variation. Each gene adds a small, cumulative effect to the trait, leading to a continuous range of skin - color shades rather than distinct categories.

Answer:

Polygenic traits like skin color are expressed through quantitative variation because multiple genes contribute to the trait, with each gene having a small, cumulative effect on the phenotype, resulting in a continuous range of values for the trait.