all cells arise from other cells

• Cell Division


  • Mitosis
  • Meiosis
• Mitosis


  • Form of cell division that occurs in the cell cycle
  • Parent cell divides to produce two genetically identical daughter cells
  • Needed for growth and tissue repair
• Mitosis


  1. Chromosomes made of two chromatids joined at centromere

  2. Chromatids separate and move to opposite poles

  3. Nuclear envelope reforms around chromosomes

  4. Cytoplasm divides to form two daughter cells
• Cell Cycle


  • Period of cell growth and DNA replication (interphase)
  • Period of cell division (mitosis)
• Interphase


  1. Cell carries out normal functions

  2. DNA unravelled and replicated

  3. Organelles replicated

  4. ATP content increased
• Prophase


  1. Chromosomes condense

  2. Centrioles move to opposite ends

  3. Spindle forms

  4. Nuclear envelope breaks down
• Metaphase


  Chromosomes line up on spindle
• Anaphase


  1. Centromeres divide

  2. Chromatids pulled to opposite poles
• Telophase


  1. Chromatids uncoil into chromosomes

  2. Nuclear envelope reforms

  3. Cytoplasm divides
• Mitosis stages vary depending on cell type and environment
• Calculating mitosis stage duration


  (Number of cells in that stage / Total cells undergoing mitosis) x Total minutes per cell cycle
• Binary fission


  Simple form of cell division where a cell replicates approximately every 20 minutes
• Binary fission


  1. DNA and plasmids replicate

  2. Cell gets bigger

  3. DNA moves to opposite poles

  4. Cytoplasm divides to form two daughter cells
• Viral replication


  • Virus lands on cell
  • Injects genetic material
  • Takes over cell to build new virus particles
  • Cell dies
  • New virus particles escape to infect next cell