Mendel performed a test cross to determine the genotype of a tall F₂ plant. If the tall F₂ plant had the genotype Tt and was crossed with a dwarf plant (tt), what would be the expected phenotypic ratio of the off spring?

 When  the tall F₂ plant had the genotype Tt and was crossed with a dwarf plant (tt)

Parents :  Tt                       tt

Gametes:  T and t       t   and  t

Offspring: Tt, Tt tt and tt.

50% tall (heterozygous) and 50 % dwarf.