How many genes typically contribute to a polygenic trait?

Polygenic traits are those characteristics that are influenced by multiple genes, often resulting in a continuous range of phenotypes. These traits include characteristics such as height, skin color, and intelligence, where the effect of many different genes combine to produce a single observable trait.

In polygenic inheritance, each gene may contribute a small, additive effect toward the overall phenotype. Because many genes can interact with one another and with environmental factors, this complexity leads to the variability seen in polygenic traits. The collective action of numerous alleles from different loci results in a continuum of traits instead of discrete categories.

This is distinct from traits governed by single genes (monogenic traits), where the presence of one or two specific alleles clearly determines the phenotype. Therefore, the correct answer accurately reflects the nature of polygenic traits, where many genes collaborate to shape the final outcome.