Microscopy

• Why are microscopes important for biology?

  They help observe small biological structures.
• How have the uses of microscopes developed over the years?

  Technology and knowledge have improved.
• What can light microscopes be used to observe?

  Cells and large subcellular structures.
• What is a key feature of electron microscopes compared to light microscopes?

  They have higher resolution and magnification.
• What small structures can electron microscopes reveal?

  Ribosomes and plasmids.
• When were electron microscopes invented in relation to light microscopes?

  After light microscopes were invented.
• What does magnification represent in microscopy?

  How many times bigger the image is.
• How do you calculate magnification?

  Magnification = image size / real size.
• If a cell's width is 0.02 mm and its image is 8 mm, what is the magnification?

  400
• Why is standard form useful in microscopy?

  It simplifies very big or small numbers.
• How do you write 0.0025 mm in standard form?

  2.5 × 10⁻³ mm
• What happens to the power of 10 when the decimal moves to the left?

  The power of 10 is positive.
• What happens to the power of 10 when the decimal moves to the right?

  The power of 10 is negative.
• What is the real width of a cheek cell with ×40 magnification and an image width of 2.4 mm?

  60 μm
• What are the steps to prepare a slide for microscopy?

  1. Add a drop of water to a slide.
  2. Cut and peel onion epidermal tissue.
  3. Place tissue in water on the slide.
  4. Add a drop of iodine solution.
  5. Cover with a cover slip.
• What are the steps to use a light microscope?

  1. Clip the slide onto the stage.
  2. Select the lowest magnification lens.
  3. Adjust the stage to focus.
  4. Use fine adjustment for clarity.
  5. Change to higher magnification if needed.
• What are the guidelines for drawing observations from a microscope?

  • Use a sharp pencil.
  • Draw smooth outlines of features.
  • No shading or coloring.
  • Label features with straight lines.
  • Include title and scale.
  • Write down the magnification used.
• Why might you add stain to a microscope slide sample?

  To make cell parts easier to see.
• What is the purpose of using a cover slip on a microscope slide?

  To protect the sample and prevent air bubbles.
• What should you avoid when placing a cover slip on a slide?

  Getting air bubbles under the cover slip.
• How does the use of stains enhance microscopy?

  They improve visibility of cell structures.
• What should the drawing of observations take up at least half of?

  The space available on the page.
• What is the significance of writing down the magnification used in observations?

  It provides context for the size of features.