Biology · Cell Cycle and Cell Division · NEET
| Main role | Interphase: growth and preparation | M phase: actual cell division |
| Sub-phases | G1, S, G2 | Mitosis (P, M, A, T) + cytokinesis |
| DNA replication | Happens (in S sub-phase) | Does not happen |
| Cell division | Does not occur | Occurs (karyokinesis + cytokinesis) |
| Duration | More than 95% of cycle | About 1 hr in a 24 hr cycle |
| Cell activity | Metabolically active, not dividing | Chromosomes condense and separate |
No. This is the most common NEET trap. During interphase the cell is metabolically very active. It grows, makes proteins, doubles its organelles and copies all of its DNA. The cell does not divide during interphase, but it is far from resting. It is preparing for division. Only true resting cells go into the separate G0 (quiescent) stage.
Yes. Interphase is very much part of the cell cycle. NCERT defines the cell cycle as having two basic phases: interphase and M phase. Interphase actually makes up more than 95% of the total cell cycle time, so it is the largest part, not something outside the cycle.
Only during M phase (mitosis). Interphase prepares the cell (growth and DNA copying), but the visible splitting into two cells happens in M phase. M phase includes karyokinesis (nuclear division) and cytokinesis (cytoplasm division). So no division occurs in G1, S or G2 which are all part of interphase.
Interphase = the phase between two divisions where the cell grows and copies DNA (G1 + S + G2). M phase = the phase where the cell actually divides (mitosis + cytokinesis). NCERT states: the M phase is when actual cell division occurs, and interphase is the phase between two successive M phases.
Interphase is much longer. In a typical 24 hour human cell cycle, M phase lasts only about 1 hour, while interphase takes the remaining more than 95% of the time. NEET often frames this as a numerical hook, so remember: long interphase, short M phase.
Identify the correct statement with regard to G1 phase (Gap 1) of interphase.
Match List-I (Phase of cell cycle) with List-II (Activity): A. G1 phase, B. S phase, C. G2 phase, D. M phase; I. Actual cell division occurs, II. Cell is metabolically active and grows but does not replicate its DNA, III. Synthesis of DNA occurs and DNA per cell doubles, IV. Proteins are synthesized while cell growth continues.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
The two basic phases are interphase and M phase (mitosis phase). Interphase is the preparation phase and M phase is the division phase. This exact wording is from NCERT.
DNA replication happens in interphase, specifically during the S (synthesis) sub-phase. In M phase the already-copied DNA is only separated into daughter cells, not synthesised.
Interphase has three sub-phases in order: G1 (Gap 1), S (Synthesis), and G2 (Gap 2). After G2 the cell enters M phase.
M phase only carries out the physical division, which is quick. All the slow work of growth, protein synthesis and DNA copying is done earlier in interphase, so interphase takes more than 95% of the cycle while M phase lasts about an hour in a 24 hour cell cycle.
No. G0 (quiescent phase) is a separate exit state where cells stop dividing and become metabolically inactive for division purposes. Interphase, in contrast, is an active preparatory phase leading toward division.
