Which statement best describes polygenic inheritance?

Which statement best describes polygenic inheritance?

• A. A single gene determines a trait
• B. Traits are inherited through mitochondrial DNA
• C. Multiple genes interact to create a continuous phenotype
• D. Traits are inherited only through the mother

Answer: (C)

Polygenic inheritance involves many genes each contributing a small amount to a trait, so their additive effects create a continuous range of phenotypes rather than distinct categories. This explains why traits like height or skin color vary gradually across individuals: it's the combined influence of multiple genetic loci, often with environmental interactions as well. This distinguishes polygenic traits from those controlled by a single gene, which tend to show discrete, separate forms. It also clarifies why mitochondrial DNA or maternal-only inheritance isn’t the defining feature of polygenic traits—polygenic variation arises from autosomal genes inherited from both parents, not from a single maternal lineage.

Polygenic inheritance involves many genes each contributing a small amount to a trait, so their additive effects create a continuous range of phenotypes rather than distinct categories. This explains why traits like height or skin color vary gradually across individuals: it's the combined influence of multiple genetic loci, often with environmental interactions as well.

This distinguishes polygenic traits from those controlled by a single gene, which tend to show discrete, separate forms. It also clarifies why mitochondrial DNA or maternal-only inheritance isn’t the defining feature of polygenic traits—polygenic variation arises from autosomal genes inherited from both parents, not from a single maternal lineage.