What are polygenes? Explain polygenic inheritance with the example of human skin color.

(N/A) Polygenes are a group of genes that together contribute to the control of a single phenotypic trait. They follow an additive effect,where the intensity of the trait depends on the number of dominant alleles present.
Polygenic inheritance is a type of inheritance in which a trait is controlled by three or more genes. Unlike Mendelian traits that show distinct qualitative differences (e.g.,purple vs. white flowers),polygenic traits show a continuous range of variation (e.g.,human height or skin color).
In humans,skin color is controlled by three genes: $A, B,$ and $C$. The dominant alleles $(A, B, C)$ contribute to the production of melanin (dark skin color),while the recessive alleles $(a, b, c)$ contribute to a lighter skin color.
$1$. $A$ genotype with all dominant alleles $(AABBCC)$ results in the darkest skin color.
$2$. $A$ genotype with all recessive alleles $(aabbcc)$ results in the lightest skin color.
$3$. $A$ genotype with a mix of dominant and recessive alleles (e.g.,$AaBbCc$) results in an intermediate skin color.
The phenotype is determined by the total number of dominant alleles present,demonstrating the additive nature of polygenic inheritance.