English: Gregor Mendel’s dihybrid cross experiment with pea plants. Dominant features are smooth and yellow and recessive features are rough and green. The parent generation, P, consists of a purebred dominant pea crossed with a homozygous recessive pea. The resulting offspring is called the F1 generation. All of the offspring will all be heterozygous and have the same phenotype, yellow and smooth. The F2 generation is produced by crossing two peas from the F1 generation. When these two heterozygous peas are crossed, the offspring will demonstrate a 9:3:3:1 ratio of 9 smooth yellow peas, 3 rough yellow peas, 3 smooth green peas, and 1 rough green pea.