His revoluntionzied the concept of parental contribution to the phenotypes of the off spring and he also coined the terms genotype and phenotype. and he is called the "father of modern genetics" because of his studies with pea plants in his simple austarian monstary in the 1800's. look him up for more detil, but these are the basic result of years of experimentation with pea palnts. here's a little FVI FACT : he wanted to cross mice but the catholic church thought that interfering with animal reproduction was normally qustion able . he changed to pea plants because they have as many different traits he could study flower color, pea pod color and shape, height, pea shapenand color and others and the churuch had no problem with him manipulating plant reproduction.