My name is Mendel and in 1857, I came up with an experiment that discovered the law of inheritance.
I bred a lot of peas which all had seven different traits. I self fertilized the peas so that they all bred true to all seven traits. I called these plants generation P, for "parent".
Then, I made the F1 generation by breeding two different plants from the P generation. I found that, even though the two parent plants had different traits, all of the plants in the F1 generation had the same one trait.
The F2 generation was the most important generation because it helped build the basis of what was needed to find out the law of inheritance. What I found was that 75% of the plants had one trait while 25% had another trait, which was not showed in the F1 generation but was in some plants from the Parent generation.