Answer:
Punnett square is a square diagram which is used to predict the genotype of the offspring produced by particular cross.
Let P and p be the alleles of the gene responsible for the flower colors in a plant.
The genotype of both the parents is given as heterozygous that is, Pp.
Two types of gametes would be formed P and p.
The cross is shown in the image below.
The cross would be result in offspring with three types of genotypes PP, Pp and pp in 1:2:1.