If the offspring of a particular cross are 100 percent heterozygous for tallness, then the most likely genotypes of the parents are TT and tt. Let T be dominant allele and t be recessive allele. The genotypes will be: TT (dominant homozygote), Tt (heterozygote), and tt (recessive homozygote). If we cross a dominant and a recessive homozygote all of the offspring will be heterozygote: TT x tt = Tt, Tt, Tt, Tt.
