Parental generation is the first generation involving two individuals that are mated to foresee or analyze the genotypes of their offspring. Their probable set of offspring would constitute the so-called first filial generation (or F1 generation). A cross between two of the offspring in F1 generation would produce a new set of progeny called second filial generation (or F2 generation).In the P generation, a true breeding pea plant with genotype YYRR is crossed with a true breeding plant with genotype yyrr.