In the G2 phase of the cell cycle, the cell has already duplicated its DNA and is now focused on growth, checking, and final prep for mitosis.

Quick Scoop: What happens in the G2 phase?

Think of G2 as the final checklist stage before a big “cell division” event.

  • DNA has already been replicated in S phase; no new DNA synthesis happens in G2.
  • The cell grows larger and replenishes its energy stores (like ATP).
  • It makes lots of proteins needed to move and separate chromosomes during mitosis.
  • Some organelles (like mitochondria, chloroplasts in plants, and Golgi bodies) are duplicated or increased.
  • The cytoskeleton begins to reorganize to prepare for chromosome movement and cell division.
  • The cell runs an important G2 checkpoint , scanning the newly copied DNA for damage and giving time for repair.
  • Cyclin–CDK complexes (especially CDK1 with cyclin A and then cyclin B) rise in activity and push the cell into mitosis.

In simple words

During G2, the cell:

  1. Has double the DNA but is not dividing yet.
  1. Bulks up in size and resources.
  1. Checks that the DNA is correct and fixes errors if possible.
  1. Arms itself with the machinery (proteins and organelles) needed to successfully go through mitosis.

Once everything passes the G2 checkpoint and CDK1–cyclin B activity surges, the cell exits G2 and enters prophase, the first stage of mitosis.

Information gathered from public forums or data available on the internet and portrayed here.