GO or quiescent stage does not serve any purpose. Actually in G0 stage cell does not go further division although it is metabollically active,but a cell in G0 stage can still go for cell division if it is call upon to do so. read more
The G 0 phase describes a cellular state outside of the replicative cell cycle. Classically, cells were thought to enter G 0 primarily due to environmental factors, like nutrient deprivation, that limited the resources necessary for proliferation. Thus it was thought of as a resting phase. read more