The dominant allele is written in capital and recessive allele in small letter. Here T which stands for tall is dominant over t which stands for dwarf. The cross is performed between Tt and Tt. The genotype of the progeny obtained is in the ratio 1:2:1. (TT: 2Tt: 1tt). The phenotype of the progeny obtained is in the ratio 3:1 (3 tall: 1 dwarf).