Microscopy

• Why are microscopes important for biology?


  They allow us to see things that are not visible to the naked eye.
• What are the main types of microscopes and their functions?


  • Light microscopes: Use light and lenses to magnify specimens, allowing us to see individual cells and large subcellular structures.
  • Electron microscopes: Use electrons to form images, providing much higher magnification and resolution than light microscopes.
• What is the function of light microscopes?


  They form an image of a specimen and magnify it to see individual cells and large subcellular structures.
• What do electron microscopes use to form an image?


  Electrons
• How do electron microscopes compare to light microscopes in terms of magnification?


  Electron microscopes have a much higher magnification than light microscopes.
• What does higher resolution in microscopy mean?


  It means the ability to distinguish between two points, resulting in a sharper image.
• What types of structures can electron microscopes help us see in detail?


  They allow us to see internal structures of mitochondria and chloroplasts, as well as ribosomes and plasmids.
• What is the formula for magnification?


  magnification = image size / real size
• What is the purpose of a microscope slide?


  To mount a specimen for viewing under a microscope
• What is the first step in preparing a slide to view onion cells?


  Add a drop of water to the middle of a clean slide
• What should you do after placing the epidermal tissue into the water on the slide?


  Add a drop of iodine solution
• Why is iodine solution used when preparing a slide?


  It is a stain that highlights objects in a cell
• What is a cover slip?


  A square of thin, transparent plastic or glass
• What should you avoid when placing the cover slip on the slide?


  Getting air bubbles under the cover slip
• What is the first step to use a light microscope on your prepared slide?


  Clip the slide onto the stage
• Which objective lens should you select first when using a light microscope?


  The lowest-powered objective lens
• What is the purpose of the coarse adjustment knob when using a microscope?


  To move the stage up or down for focusing
• How do you achieve a clear image after roughly focusing the slide?

  Use the fine adjustment knob
• What should you do if you want to see the slide with greater magnification?

  Swap to a higher-powered objective lens and refocus
• How should subcellular structures be drawn in your observations?


  In proportion to their actual size