Five Mark Questions :
(a) What is polygenic inheritance? explain with the help of a suitable example.
(b) How are pleiotropy and Mendelian pattern of inheritance different from polygenic inheritance?

• Polygenic inheritance is when more than one gene controls a character. It is also known as quantitative inheritance where two or more different pair of alleles which have a cumulative effect on governing quantitative characters.

Example of polygenic inheritance is white spotting in mice, green color in wheat.

• Mendelian inheritance revolves around the law of dominance, the law of independent assortment and law of segregation of gametes and gives clear ratio and does not talk about the mixing of two characters. Here, one gene controls one trait.

• Pleiotrophy is when one gene controls multiple characters.