A growing cell undergoes cell cycle that essentially consists of two periods, inter phase (I-phase), or resting phase and Mitotic phase (M-phase). Interphase comprises G1 (Gap 1), S (Synthesis) and G2 (Gap II) G1 is the period between the end of mitosis and start of S phase RNA and proteins are synthesized during this phase. S is the specific part of the interphase during, which DNA synthesis occurs or DNA is replicated in this phase. G2 period is the interval between the end of S-phase and start of mitosis. RNA and new proteins to be used for mitosis are synthesized. The decision of cell division occurs in G1 -phase. The cell would normally proceed to mitosis (M-phase) without interuption when it hasentered S-phase. Mitosis (M-phase) consists of division of nucleus or karyokinesis followed by division of cytoplasm or cytokinesis.