Question

Differentiate between pleiotropy and polygenic inheritance.

Answer 1

Aspect	Pleiotropy	Polygenic Inheritance
Definition	Pleiotropy is the ability of a single gene to influence more than one trait.	Polygenic inheritance involves the inheritance of a trait that is influenced by multiple independent genes.
Gene effect	A single gene affects multiple phenotypic traits.	Many genes, each with a small and similar effect, cumulatively influence a single trait.
Example	Sickle cell anemia in humans is an example of pleiotropy where one gene affects multiple symptoms.	Human skin color is an example of polygenic inheritance controlled by several pairs of genes.
Phenotypic outcome	One gene leads to multiple phenotypic effects that may be seemingly unrelated.	Multiple genes additively contribute to the phenotype, creating a continuous range of variation.