Answer:
In second generation, ratio of tall (dominant) to short (recessive) plants = 3:1.
Step-by-step explanation:
When Mendel crossed two pure breeding parents for plant height, in filial 1 (F1) generation he got all the plants with tall height. But when he further allowed to self-pollinate F1 generation plants, he got tall to short ratio as 3:1 in F2 generation.
The crosses are depicted as under:
Parental: TT x tt
/ \ / \
F1 : Tt Tt Tt Tt
When F1 were self pollinated as depicted below he got 3:1 ratio for tall and short height:
Tt x Tt
/ \ / \
F2: TT Tt Tt tt
The plants with genotype TT, Tt, Tt will be tall heighted while the ones with tt genotype will be short heighted.