Explain Mendel’s contribution.

•Mendel performed experiments on Pisum sativum (garden pea) for explaining the transmission of characteristics (traits) from parents to their offspring.

•He proposed the laws of inheritance.

•He studied the inheritance of some contrasting characters like height of plant, color of seeds, etc.

•He crossed a tall plant (with TT traits) with a dwarf plant (with tt trait), and obtained all tall plants in F1 generation. Thus, only one of the two parental characters was expressed in F₁ generation.

•When the plants of F₁ generation were crossed, 25% dwarf plants and 75% tall plants were obtained in F2 generation.

•Thus, in F₁ generation both the characters of tallness and dwarfness were inherited from the parents but only the character of tallness was expressed.

•In other experiment, Mendel selected two different traits in a plant. He crossed a plant having yellow and round seed with a plant having green and wrinkled seeds.

•In F₁ generation, all the plants were with yellow and round seeds indicating that yellow and round seed traits are expressed.

•When the plants of F₁ generation were self-pollinated, the plants along with new combinations (yellow and wrinkled seeds, green and round seeds) along with parental combinations (yellow and round seeds, green and wrinkled seeds) were obtained in F₂ generation.

•This indicates that yellow seeds/green seeds traits and round seeds/wrinkled seeds traits are independently inherited.