When Mendel crossed two plants that were hybrid for stem height (Tt) three fourths ( and frac34) of the F1 plants had short stems.?

This indicates that the short stem trait is dominant. Mendel's expected ratio for a monohybrid cross with dominance is 3:1, with three quarters (75%) showing the dominant trait (short stems) and one quarter (25%) showing the recessive trait (tall stems).