The answer is George Mendel. He is known as a father of genetics because of his work on pea plant. He discovered that genes are present in a form of pair and there are two alleles to a single gene which manifest the traits.
His work with pea plant clearly explains the fact that there are two alleles of a single gene, for example:
Pea shape- round or wrinkled
Pod color- green or yellow
He is know as father of genetics by introducing The law of inheritance