Aadya Isai

Cell Cycle — How Cells Prepare to Divide

The cell cycle is the full series of steps a cell goes through before dividing.

Key phases:

1. Interphase

   • This is where the cell spends most of its life.

   • It has three sub-phases:

     
     

     • G1 phase (“gap 1”): Cell grows, does normal functions, makes organelles.

     • S phase (“synthesis”): DNA is replicated, so each chromosome is copied.

     • G2 phase (“gap 2”): Cell makes more proteins and gets ready for division.

     
     

2. M phase (“Mitosis” phase)

   • This is when the cell actually divides.

   • M phase itself includes:

     
     

     • Mitosis (division of the nucleus)

     • Cytokinesis (division of the cytoplasm) — splitting the rest of the cell into two.