Final answer:
A polygenic trait is one that is influenced by multiple genes, each possibly having multiple alleles, resulting in a wide range of variations for the trait. Examples of polygenic traits are height, skin color, and eye color, which exhibit continuous variation and can be influenced by environmental factors.
Step-by-step explanation:
A trait that forms through the interaction of several genes is called a polygenic trait. This means that the trait is controlled by more than one gene, and each gene may have two or more alleles. Examples of polygenic traits include characteristics such as human height, skin color, and weight. Unlike traits governed by a single gene with two alleles, polygenic traits show a wide range of variation because they are the result of the combined effect of numerous genes. In the development of certain traits, such as eye color, which is influenced by at least eight genes, the concept of epistasis comes into play where multiple genes interact with one another, further influencing the phenotype. Traits that are measurable and show continuous variation, often influenced by environmental factors as well, are typically polygenic. This contributes to the genetic diversity and adaptability of a species.