The Punnett square
The Punnett square graphically illustrates the basic rules of heredity. It is a pictorial genetic diagram in a grid form.
He punted (Punnett) the ball into the gridiron (grid).
Mendel’s green pod and yellow pod experiment shows how the parent pods could still pass on the yellow trait even when they were green pods. He called the green pod trait the dominant trait and the yellow pod the recessive trait.
Is a green pod but has a yellow pod allele from one parent and a green pod allele from the other.
Is a green pod too and also has a yellow pod allele from one parent and a green pod allele from the other.
The probability is that there is a 75% chance this generation of pea pods will have green pods and 25% chance they will have yellow pods.