Biology · Cell Cycle and Cell Division · NEET
It is metabolically ACTIVE. NCERT says cells in the quiescent stage 'remain metabolically active but no longer proliferate.' So the word 'inactive' only means it is not dividing — it is NOT switched off. NEET loves this trap: a 2023 PYQ marked the statement 'During G0 the cell is metabolically inactive' as INCORRECT.
At the end of G1 phase. The cell decides to leave the cycle in G1, BEFORE DNA is copied in S phase. So the exit is G1 to G0. It does not happen after S, G2, or M. A 2020 PYQ tested exactly this and the answer was G1 phase.
No. G1 is an active gap phase inside the cell cycle where the cell grows and prepares to divide. G0 is OUTSIDE the cycle — the cell has stepped off the cycle and is not preparing to divide. Both look similar because DNA is not being copied in either, but G1 leads to S phase while G0 does not (unless the cell is called back).
Yes, some can. NCERT says cells stay in G0 'unless called on to do so depending on the requirement of the organism.' For example, liver cells re-enter the cycle after injury. But some cells like most neurons and heart cells normally stay in G0 permanently.
NCERT gives heart cells as the classic example ('do not appear to exhibit division'). Nerve cells and mature muscle cells are other common examples. These divide only occasionally or not at all, only to replace cells lost by injury or cell death.
G0 is a resting state that branches OUT of interphase at the end of G1. It is not one of the three normal interphase sub-phases (G1, S, G2). Treat G0 as a separate quiescent/exit state, not a step in the G1 to S to G2 sequence.
Cell in G0 phase :
Some dividing cells exit the cell cycle and enter vegetative inactive stage. This is called quiescent stage (G0). This process at the end of:
Statement 1: During G0 phase of cell cycle, the cell is metabolically inactive. Statement 2: The centrosome undergoes duplication during S phase of interphase. Choose the most appropriate answer:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
G0 is a resting stage where a cell has left the cell cycle and stopped dividing, but stays metabolically active. Cells enter it from the end of G1 when they do not need to divide.
'Quiescent' means resting or inactive with respect to DIVISION. The cell is not proliferating (not making new cells), even though its normal metabolism continues. That is why it is called the quiescent stage.
No. G0 cells exit at the end of G1, which is before S phase, so DNA replication has not happened. They carry the normal 2n, 2C content and do not copy their DNA while in G0.
Not always. Some G0 cells can be called back into the cycle when the organism needs repair or growth. But cells like most neurons and heart muscle usually remain in G0 permanently and do not divide again.
