What is mitosis?

Mitosis is cell division producing two genetically identical diploid daughter cells. Phases: (1) Prophase — chromosomes condense, nuclear envelope breaks down, spindle fibers form; (2) Metaphase — chromosomes line up at cell equator; (3) Anaphase — sister chromatids separate, pulled to opposite poles; (4) Telophase — nuclear envelopes reform around each set; (5) Cytokinesis — cytoplasm divides, two cells separate. Mnemonic: PMAT (Prophase, Metaphase, Anaphase, Telophase). Uses of mitosis: growth (single fertilized egg → trillions of cells); tissue repair (healing wounds, replacing dead cells); asexual reproduction (in some organisms). Versus MEIOSIS: produces four genetically different haploid gametes (sperm, eggs); occurs in reproductive cells only; involves two divisions and genetic recombination through crossing over. Meiosis introduces genetic variation; mitosis preserves it. Cell cycle: G1 (growth) → S (DNA replication) → G2 (preparation) → M (mitosis). G0 — non-dividing state for cells like neurons. Cell cycle regulation involves checkpoints; failure can lead to cancer (uncontrolled cell division). Tumor suppressor genes (p53) and oncogenes regulate the cycle; mutations disrupt control.