Question

If Mendel had crossed a true breeding dominant plant with a true breeding recessive plant, in which of the three generations is the recessive trait visible?
F1 generation only
P generation only
F1 generation and F2 generation
P generation and F2 generation

Answer 1

P generation and F2 generation.

Reason: the recessive parent in the P generation shows the recessive trait. All F1 offspring are heterozygous and show the dominant trait. In the F2 (from F1 × F1) the recessive phenotype reappears in about 1/4 of the offspring.