In a Punnett square for a cross between a tall plant (TT) and a short plant (tt), the possible genotype of the offspring can be determined as follows:
The tall plant (TT) can produce gametes with the allele T, while the short plant (tt) can produce gametes with the allele t. When these gametes are combined in a Punnett square, the possible combinations for the offspring are:
- From TT (T from tall plant) combining with tt (t from short plant):
- T from TT and t from tt = Tt
- T from TT and t from tt = Tt
So all the offspring will have the genotype Tt.
Therefore, the genotype of the offspring from the cross between TT and tt is Tt.