Polygenic traits are controlled through which of the following ways.

• A. Multiple alleles for one gene
• B. Multiple genes
• C. Epistasis
• D. Penetrance

Answer: (B)

Verified step by step guidance

1. Understand the concept of polygenic traits: These are traits that are controlled by more than one gene, often resulting in a continuous range of phenotypes.
2. Recognize that polygenic traits are influenced by multiple genes, each contributing to the overall phenotype. This is different from traits controlled by a single gene with multiple alleles.
3. Consider examples of polygenic traits, such as human height or skin color, which are influenced by the combined effect of several genes.
4. Differentiate polygenic inheritance from epistasis, where one gene can affect or mask the expression of another gene, and penetrance, which refers to the proportion of individuals carrying a particular variant of a gene that also express an associated trait.
5. Conclude that polygenic traits are controlled by multiple genes, which collectively influence the phenotype, rather than by multiple alleles of a single gene or through epistasis or penetrance.