LIFE SCIENCE

Detailed explanation-1: -A polygenic inheritance in human beings is skin colour. Polygenic or quantitative inheritance occurs when several genes occupying different loci on the same homologous pairs of chromosomes govern one trait. Inheritance of colour in human beings is an example of polygenic inheritance.

Detailed explanation-2: -Skin color in humans is controlled by 3 genes. Hence it is an example of quantitative inheritance also called polygenic inheritance in which a phenotypic trait is controlled by many genes. Such genes that control many traits are called polygenes or cumulative genes. Thus the correct answer is option D.

Detailed explanation-3: -Explanation: Three genes determine the colour of a person’s skin. As a result, there is a polygenic inheritance. These three genes are found at three separate loci, and each dominant gene is in charge of a specific amount of melanin synthesis.