Required Practical: Microscopy

• What is the main part of the optical microscope where the slide is placed?

  The stage
• How does light pass through the microscope slide?

  It passes up through the slide
• What are the lenses above the stage called?

  Objective lenses
• What are the two focusing dials on the microscope?

  Coarse and fine focusing dials
• Which objective lens should be selected first for viewing?

  The lowest power objective lens
• Why should you look at the microscope from the side while adjusting the lens?

  To avoid damaging the slide
• How do you calculate the total magnification of the microscope?

  Multiply eyepiece magnification by objective magnification
• What should you do after achieving focus with a low-power objective lens?

  Select a higher power objective lens
• What might you see when looking at animal cells under a microscope?

  Nucleus, cytoplasm, and cell membrane
• What can be seen in plant cells under a light microscope?

  Cell wall, cytoplasm, and nucleus
• What additional structures might be visible in plant cells?

  Vacuole and chloroplasts
• How do you include a magnification scale in your drawing?

  Measure the diameter of the field of view
• What should you do to show the magnification on your drawing?

  Write the magnification, e.g., 100 times
• What are the steps to use an optical microscope to view a prepared slide?

  1. Place the slide on the stage and secure it with clips.
  2. Select the lowest power objective lens.
  3. Position the objective lens close to the slide using the coarse focusing dial.
  4. Look through the eyepiece and adjust the coarse focusing dial until cells are in focus.
  5. Use the fine focusing dial for clear focus.
  6. Calculate total magnification by multiplying eyepiece and objective magnifications.
  7. Optionally switch to a higher power objective lens and refocus.
  8. Draw and label the cells, including a magnification scale.