The process of cell division is called the cell cycle. G1 phase - Cell grows in size and cellular contents (e.g. organelles) duplicate so that the new cells will have enough to function. S phase - The chromosomes in the nucleus are duplicated. G2 phase - Cell continues to grow and prepares for mitosis. Mitosis - The duplicated chromosomes are separated and pulled to opposite poles of the cell and the nucleus divides. Then the cyctoplasm and cell membrane divide, forming identical cells.