In polygenic inheritance, the phenotype shows a continuum of variation.

In polygenic inheritance, the phenotype shows a continuum of variation.

• A. The phenotype is discrete
• B. The trait is inherited through single gene
• C. Only recessive alleles determine it
• D. The phenotype typically shows a range of values

Answer: (D)

Polygenic inheritance involves many genes, each adding a small effect to a trait. When these small effects accumulate, they produce a continuous range of phenotypes rather than distinct categories. That’s why traits like height or skin color vary gradually across individuals and tend to form a spectrum in the population, often influenced by environmental factors as well. In contrast, a single-gene trait tends to be discrete because one gene largely determines the outcome, producing distinct classes rather than a smooth range. It isn’t accurate to say only recessive alleles determine a polygenic trait, since multiple genes with different allele forms contribute to the overall variation. The idea of a continuous range best captures the essence of polygenic inheritance.

Polygenic inheritance involves many genes, each adding a small effect to a trait. When these small effects accumulate, they produce a continuous range of phenotypes rather than distinct categories. That’s why traits like height or skin color vary gradually across individuals and tend to form a spectrum in the population, often influenced by environmental factors as well. In contrast, a single-gene trait tends to be discrete because one gene largely determines the outcome, producing distinct classes rather than a smooth range. It isn’t accurate to say only recessive alleles determine a polygenic trait, since multiple genes with different allele forms contribute to the overall variation. The idea of a continuous range best captures the essence of polygenic inheritance.