Microscope - cells

• What is the aim of the investigation described?

  Investigate biological specimens using microscopes
• What equipment is needed for the investigation?

  • Light microscope
  • Microscope slide
  • Cover slip
  • Onion
  • Forceps
  • Iodine solution
  • White tile
  • Scalpel
  • Prepared plant and animal cell slides
• Why is iodine solution used in the method?

  To stain the cells for visibility of structures
• What is the first step in the method for preparing the onion slide?

  Peel off an epidermal layer using forceps
• How should the onion tissue be placed on the slide?

  It should lie flat on the slide
• How many drops of iodine solution should be added?

  Two drops
• What should be done to avoid air bubbles when placing the cover slip?

  Lower the other side slowly using forceps
• What should be done with excess stain?

  Soak it with paper towels
• What is the first action after placing the slide on the microscope stage?

  Turn the nosepiece to select a low power objective
• What should you do before looking into the eyepiece?

  Use the coarse adjustment knob to raise the stage
• Why is it important to move the stage away after touching the cover slip?

  To avoid breaking the slide
• What should be done after selecting a high power objective?

  Repeat the focusing process with the fine adjustment knob
• What should be included in the labelled drawing of the cells?

  Features like cell wall and nucleus
• What should you do after making the drawing?

  Write down the magnification
• What is the final step in the method?

  Repeat the steps using a prepared slide
• What safety precautions should be taken during the experiment?

  • Wear safety goggles when handling iodine
  • Be careful with broken glass if a slide breaks