Monohybrid Cross.

Definition.

After establishing 14 pure – breeding lines of seven characters, he cross-fertilized plants that differed in one character only. The offspring of such a cross were called monohybrids.

Parental generation.

He cross-fertilized a true breeding round-seeded male plant with a true breeding wrinkled-seeded female plant. He called it first parental generation (P1). F1 generation. Their offspring were called F1 or first filial generation. All F1 offspring were round like one of the parents. Wrinkled phenotype did not appear at all. Round dominated wrinkled. Its dominance was complete because no offspring intermediate between parents was found.

He called  The trait that appeared in F1 as dominant;

 While the trait, which was masked, as recessive.

F2 Generation. Then Mendel allowed self-fertilization among F| monohybrids to raise F2 progeny.

As a result of monohybrid cross ¾of F2 were round and ¼ were wrinkled. For All traits. Mendel got similar results and the same 3:1 ratio in offspring of monohybrid crosses for all the seven contrasting pairs of traits.

F3 Generation. Mendel proceeded a step ahead. He selffertilized F2 plants to raise F3.

Observation.

He noted that  1/3 of F2 round produced only round, while  2/3 of F2 round produced both round and wrinkled in 3:1 ratio; but  F2 wrinkled produced only wrinkled. Conclusion. He concluded that 1/3 of F2 rounds were true breeding like P1 round, and 2/3 of F2 rounds were monohybrids like F1 round.