Question

Differentiate between the following:

Monogenic inheritance and Polygenic inheritance

Answer 1

Basis of Difference	Monogenic inheritance	Polygenic inheritance
Genes involved	A monogenic trait is controlled primarily by a single gene.	A polygenic trait is controlled by several non-allelic genes acting together.
Type of variation	Monogenic inheritance commonly produces distinct, discontinuous categories of phenotype.	Polygenic inheritance commonly produces continuous variation across a range of phenotypes.
Effect of genes	The alleles of the single gene determine the trait’s categories.	Each contributing gene usually has a small effect, and their combined effects influence the trait.
Examples and analysis	Mendelian pea traits, such as seed shape, are examples of monogenic inheritance and are often analysed using counts and ratios.	Human skin colour is an example of polygenic inheritance, and its continuous variation is commonly analysed statistically.