The science of heredity and variation is called Genetics.
Mendel conducted breeding experiments in a plant called garden pea (Pisum sativum) with contrasting pair of characters, found that only one character of the pairs appeared in the first generation but both the characters appeared in the subsequent generation. On the basis of these results of his experiments he put forth the various principles of inheritance. He also suggested that each character is controlled by a pair of factors which are now called as genes.