Question

The second generation of purebred cross of -hom-ozygo us recessive organism, with a —hom-ozygous dominant organism, contain a ratio of approximately _______ expressed dominant traits to recessive traits.
A. 2:1
B. 1:1
C. 1:3
D. 3:1

Answer 1

Answer:

D. 3:1

Explanation:

Gregor Mendel, in one of his numerous studies, performed a cross between purebred dominant (TT) pea plants and purebred recessive (tt) pea plants. All the offsprings of this cross appeared heterozygous tall (Tt) in the F1 generation.

However, when he self-crossed the F1 generation i.e. Tt × Tt, Mendel obtained a phenotypic ratio of 3 tall plants (dominant traits) : 1 short plant (recessive). This showed that the masked gene (recessive) was still present.