A plant with either the PP or Pp genotype has purple flowers, while a plant with the pp genotype has white flowers.Cross two heterozygous purple flowered plants.What is the phenotypic ratio of their offspring? Phenotypic Ratio (Purple: White) Solution PP x Pp=> PP, Pp,PP,Pp=>for heteryzygous we will consider the two=Pp The ratio (purple to white is)is 50%=1/2.