Nuclear division- mitosis, viruses and binary fission

• Prophase

  • Chromatin condenses to chromosomes
  • Nuclear membrane breaks down
  • Centrioles migrate to poles
  • Spindle fibres develop
• Prophase acronym


  DNA- Do

  Nuclear membrane- Not

  Centrioles- Call

  Spindle fibres- Suhana
• Metaphase

  • Chromosomes visible as 2 chromatids
  • Align in the middle (equator)
  • Spindle fibres attach to centromeres of chromosomes
• Anaphase

  • Spindle fibres shorten
  • Centromeres split
  • Chromatids are away (separate)
  • Formed as chromosomes
• Telophase

  • 2 groups of chromosomes
  • Start to uncoil
  • Nuclear membranes start to reform
• cytokenesis


  Cell membrane and cytoplasm split into 2 cells
• Division in viruses

  1. Protein attachments on the outside attach to receptors on cell membrane
  2. Enters cell
  3. Viral DNA/RNA in operates into host‘s DNA (enzymes attach to the host’s chain) and gets replicated
  4. New viruses made in shell
  5. New viruses burst out of cell
• Binary division

  1. DNA and plasmids replicate
  2. Copy of DNA and original DNA attach to cell membrane
  3. Cell membrane ‘pinches’ inwards
  4. New cell wall forms between 2 copies of DNA