When Mendel crossed pure-bred tall plants with pure-bred dwarf pea plants, he found that only tall pea plants were produced in the `F_(1)` genertion. Now, when Mendel further crossed the tall pea plants of the `F_(1)` generation , he found that tall planst and dwarf plants were obtained in the ration `3 : 1` in the `F_(2)` generation. Mendel noted that all the pea plants produced in the `F_(2)` generation were either tall or dwarf. There were no plants with intermediate height ( or medium height) in-between the tall and dwarf plants . In this way, is because if the traits of showed that the traits (like tallness and dwarfness) are inherited independently. This is because if the traits of tallness and dwarfness had blended (or mixed up), then medium sized pea plants would have been produced.