Who was gregor mendel, and how did he discover the basis of heredity?

Gregor Mendal is known as the father of genetics. Mendal while a monk, used math to discover the basics of heredity by crossing pea plants with different characteristics for the f1 generation but when he crossed the f1 generation with a different pea plant he realized the traits that were in the original crossing to get f1 generation didn't show up until the f2 generation.

Used the punnett square to explain inheritance of traits observes in pea plant. Half trait come from one parent and the other.