Answer:
Tt, Tt, tt, tt.
Phenotype: two tall and two dwarfs
Explanation:
The F1 generation will be the crossing of True tall and true dwarf plants to give all tall plants. Kindly note that the genotype for true tall plants is represented by TT, and the genotype for true dwarf plants is represented by tt. The crossing of the two true tall and true short gives Tt, Tt, Tt, Tt; in which the phenotype = all the plants are tall.
If the F1 generation is crossed with the true dwarf plants that is; Tt with tt. It gives us:
T t t t.
Tt, Tt, tt, tt. So, the phenotype is two tall and two dwarfs and the genotype is 2 of Tt and 2 of tt.