Cell Cycle

• In cell division old cells are split and new cells are form and the repetition of this process is called as cell cycle.
• Cell cycle has four stages:
• Gap1 Phase (G1)
• Synthesis Phase (S)
• Gap2 Phase (G2)
• Mitosis Phase (M)
• G1, S and G2 phase are collectively known as Inter phase.

1. Gap1 Phase (G1):
• Cell is prepare for cell division.
• At restriction point cell is committed to division and moves into S phase.
2. Synthesis Phase (S):
• DNA replication occurs.
• Each chromosome now consist of two sister chromatids.
3. Gap2 Phase (G2):
• Cell grows more
• Organelles & Protein develop in preparation of cell division.
4. Mitosis Phase (M):
• Mitosis followed by cytokineses (Cell separation).
• Formation of two identical daughter cells.
• It include two steps.
• Karyokinesis: Division of nucleus. It has four stage Prophase, Metaphase, Anaphase and Telophase.
• Cytokinesis: Division of cytoplasm.

 

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