Question

Select the incorrect statement regarding polygenic inheritance.
[0.7 mark]

• A. Multiple genes are involved in such inheritance
• B. Heights in human are one of the examples of polygenic inheritance
• C. Such inheritance always correlated with pleiotropy
• D. If the skin colour in human is controlled by three genes A, B and C then the genotype aabbcc will show lightest skin colour

Answer 1

The correct option is C Such inheritance always correlated with pleiotropy

The inheritance of traits which are controlled by two or more genes is called polygenic inheritance. Heights and skin colour in human are examples of polygenic inheritance. The genotype aabbcc (recessive homozygous condition) w.r.t. human skin colour will show lightest skin colour.

When a single gene exhibits multiple phenotypic expressions, the gene is called pleiotropic gene and the mechanism is called pleiotropy.

Hence, polygenic inheritance is not correlated with pleiotropy.