Question

In the F₂ generation from the cross Tt × Tt, what phenotypic ratio did Mendel observe?

Options

• 2:1 (Tall:Dwarf)

• 1:1 (Tall:Dwarf)

• 3:1 (Tall:Dwarf)

• 1:3 (Tall:Dwarf)

Answer 1

When F₁ heterozygous plants (Tt) were self-crossed, the F₂ generation showed a 3:1 phenotypic ratio of tall to dwarf plants. This occurs because the Punnett square produces genotypes in a 1:2:1 ratio (TT:Tt:tt), where both TT and Tt express the tall phenotype, resulting in 3 tall plants for every 1 dwarf plant.