Question

what happens in G2 phase
Answer in points​

Answer 1

The second growth phase follows the S phase (synthesis). Past the S phase, the cell goes through a quality control point where (like in every transition point of the cycle) the integrity of the DNA is checked. After this, the cell enters the second growth phase where the nuclear envelope envelopes the nucleus. In this phase two centrosomes have formed (courtesy of the first growth phase); in animal cells, these centrosomes have two centrioles.

It is important to note that the DNA replicated in the S phase has not condensed into chromosomes yet. The organelles necessary for the cell division (in M phase) are also synthesized in the S phase. The microtubules that will be used to mobilize the chromosomes in M phase are assembled at G2.

Now, all of the tasks accomplished during G2 can only be properly achieved if the events before G2 have gone as planned. Pit stops termed checkpoints are present for the sole purpose of ensuring that the cell has successfully finished all the tasks it is supposed to achieve after each phase. The cell cycle comprises of three checkpoints, namely, M/G1(Exit M), G1/S (Enter S) and G2/M (Enter M).