Gregor Mendel was an Austrian Monk who lived in the 1800s. Mendel was studying to be a science teacher, and he learned science, math, and botany.
Mendel became interested in the pea plants he was working on. He wondered how each pea plants traits were passed to the next generation.
Mendel began to study the way traits are passed from one generation of pea plants to the next. He deliberately crossed specific pea plants to see the offsprings.
He found the same thing for every time he tried this, whether it was on humans, plants, or animals. When he crossed two pea plants with different colored flowers, all of their offsprings had purple flowers.
He discovered, that in the 3rd generation, every single time he tried this, the ratio of 3 to 1 was relevant when he was comparing a trait, meaning that when he compared the traits of purple to yellow flowers, there were 3 purple to 1 yellow.