Mitosis

• Where do plant cells undergo mitosis?

  At shoot and root tips in meristems
• What is the characteristic of cells in the meristems?

  They are totipotent and can differentiate
• What does the mitotic index represent?

  The ratio of cells undergoing mitosis
• How is the mitotic index calculated?

  By counting mitotic cells and total cells
• What equipment is needed to calculate the mitotic index?

  An optical microscope and garlic root tip
• What is the method for preparing a garlic root tip for mitotic index calculation?

  1. Cut a 5mm sample of the root tip.
  2. Transfer to HCl for 5 minutes.
  3. Transfer to cold distilled water for 5 minutes.
  4. Dry on filter paper.
  5. Macerate on a microscope slide.
  6. Stain with toluidine blue for 2 minutes.
  7. Lower cover slip carefully.
  8. Squash the slide gently.
  9. Adjust microscope for clear image.
• What is the purpose of using toluidine blue stain?

  To make chromosomes visible
• Why is it important to avoid air bubbles under the cover slip?

  They may distort the image
• What should be done if a cut occurs from handling a scalpel?

  Elevate cuts and seek medical assistance
• What are the safety precautions for using hydrochloric acid and toluidine blue?

  • Wear eye protection.
  • Avoid skin contact.
  • Wash off immediately if contact occurs.
• What is the risk associated with broken glass in the lab?

  Cuts from sharp objects
• What should be done if glass cuts occur?

  Elevate cuts and apply pressure
• What is the risk level associated with the hazards mentioned?

  Low
• What are the hazards and risks associated with the experiment?

  • Hydrochloric acid: Harm/irritation to eyes or cuts.
  • Toluidine blue: Harm/irritation to eyes or cuts.
  • Scalpel: Cuts from sharp object.
  • Broken glass: Cuts from sharp object.