cell cycle and mitosis

• Cell division in eukaryotic cells can occur through mitosis or meiosis, while prokaryotic cells replicate by binary fission and viruses replicate by injecting their nucleic acid into host cells
• Cell cycle


  Includes all the stages to create a new cell, consisting of interphase (G1, S, G2) and nuclear division (mitosis or meiosis), followed by cytokinesis
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase
• Mitosis


  • Involves one round of cell division, resulting in two genetically identical diploid cells
  • Purpose is growth and repair, e.g. immune response through clonal expansion of B cells
• In prophase, chromosomes condense and become visible, the nuclear envelope disintegrates, and the centrosomes move to opposite poles
• In metaphase, the chromosomes align along the equator of the cell, with spindle fibers attached to the centromeres and chromatids
• In anaphase, the sister chromatids separate and are pulled to opposite poles by the retracting spindle fibers, requiring ATP
• In telophase, the chromosomes become longer and thinner, the spindle fibers disintegrate, and the nuclear envelope reforms
• Cytokinesis is the final stage where the cytoplasm splits, resulting in two new genetically identical cells
• Mitotic index


  The ratio of cells in mitosis to the total number of cells in a field of view