So in this phase, our cell basically continues producing the proteins and the organelles that are needed by that cell. So once the chromosomes are replicated and the chromosome number is doubled, the cell enters the G Two phase. During this phase, the cell prepares for cell division by making sure it contains enough proteins and organelles. That means protein synthesis and organelle production continues in the G Two phase. Now, at the end of the G Two phase, just like the G One phase contains a checkpoint, the G Two phase also contains a checkpoint at the end. At the checkpoint, the cell basically checks for the level or the concentration of a certain type of protein known as the mitosis promoting factor or MPF.