Final answer:
Polygenic traits follow a continuous variation inheritance pattern, involving multiple genes and a range of phenotypes typically represented by a bell-shaped curve. Examples include height, skin color, and eye color, which all show the complex interplay of multiple genes contributing to a trait.
Step-by-step explanation:
Polygenic traits follow a continuous variation inheritance pattern, which means that the traits exhibit a wide range of expressions and typically result in a bell-shaped curve when the frequency of the phenotypes is graphed. This pattern occurs because the trait is controlled by multiple genes, often with each gene having multiple alleles. As opposed to traits controlled by a single gene, polygenic traits can have many phenotypes.
For example, human height is influenced by at least three genes, each with two alleles. Individuals with a majority of dominant alleles (e.g., AABBCC) may be very tall, while those with a majority of recessive alleles (e.g., aabbcc) might be very short. Most individuals will have a mixture of dominant and recessive alleles (e.g., AaBbCc), which produces the majority of heights within the middle of the range. This results in few individuals at the extreme ends of the spectrum and most in the middle, contributing to the classic bell-shaped curve associated with polygenic inheritance.
Skin color, hair color, and eye color are other examples of polygenic traits, illustrating the complexity and diversity of human phenotypes. It's this capability for continuous variation and influence from multiple genes that support the wide range of characteristics we observe in natural populations.