Question

Pure-tall (TT) pea plants are crossed with pure-dwarf (tt) pea plants. The pea plants obtained in F₁ generation are then self pollinated to produce F₂ generation.

1. What do the plants of F₁ generation look-like? Justify your answer.
2. What is the ratio of pure-tall plants to pure-dwarf plants in F₂ generation?

Answer 1

i. All plants of the F generation will have the genotype Tt when pure tall (TT) and pure dwarf (TT) pea plants are crossed. All of the F₁ plants will be tall because T (tall) is dominant over t (dwarf):

	T	T
t	Tt	Tt
t	Tt	Tt

Here 100% tall plant where ‘T’ is a dominant character (Tallness).

ii. Two members of the F₁ generation are crossed to create the F₂ generation.

	T	t
T	TT	Tt	F2 generation
t	Tt	tt

As a result, the ratio of pure tall to pure dwarf is 25%, or 1 : 1.