Like begets like is an important and universal phenomenon of life. The living beings produce offspring’s of their own kinds.
The young ones resemble their parents and also with each other, yet there are considerable variations amongst themselves. The people from different parts of the world differ in appearance and people from one family have many characters in common.
These similarities and variations in characters pass from one generation to another. The process of transmission of characters through generations is known as heredity. The degree of variations among the offsprings and between the offsprings and parents is known as variation. The science dealing with the study of heredity and variation is known as genetics (Bateson, 1905).