In fact the cell doubles in size during the phase known as the G One phase. Now towards the end of the G One phase is a checkpoint known as the restriction point. And if the conditions are favorable and if the requirements have been met by the cell, the cell can basically commit itself to the process of cell division by exiting the G One phase and entering the next phase of interface known as the F phase. However, what happens if the cell doesn't actually want to divide? What happens if the conditions are not favorable or if the requirements have not been met? In this case the cell exits the G One phase and it exits Interphase entirely and it enters a completely different phase known as the G Not phase which is the resting phase of the cell cycle.