In the F1 generation, the parents are Purebred. When looking at the Punnett square diagrams, the genetics of the parents are GG and gg. In the F2 generation the parents are Hybrid. This is because when looking at the Punnett square diagrams, the genetics of the parents are Gg and Gg. Parents who are opposite purebreds cannot have offsprings that are purebred and instead will have hybrid offsprings.