Explain the polygenic inheritance pattern with the help of a suitable example.

Polygenic inheritance – In this one character is controlled by three or more genes and each gene contributes to phenotype so it is the additive (cumulative) effect of all the genes that is expressed. e.g. Human skin colour is controlled by three genes, where dominant genes (ABC) are responsible for dark skin colour and recessive ones (abc) is responsible for light skin colour. AABBCC X aabbcc Dark skin light skin Gamete F1 – Intermediate skin colourAaBbCc abc ABC