Mendel crossed the dominant purple colour flowered plant with the recessive white colour flowered plant. The F 1 generation produced the heterozygous purple colour flowered (Pp) plants. When two heterozygous pea plants (Pp) are crossed in the F2 generation represented by Pp x Pp, the gametes formed are P and p. Out of the offspring produced, 3 are purple colour flowered plants and 1 is white colour flowered plant. Thus the phenotypic ratio is 3: 1 with one out of four plants being white colour flowered pea plant. When expressed in percentage it is 25%.