cell biology : microscopy

• What should you be able to describe by the end of the video?

  The advantages of an electron microscope over a light microscope
• What is the main function of microscopes?

  To magnify images of specimens
• What did early microscopes look like?

  They looked much simpler than modern microscopes
• What have light microscopes allowed scientists to discover?

  Important structures inside cells, such as the nucleus
• What is a limitation of light microscopes regarding magnification?

  They have a limited magnification that cannot easily view structures inside the nucleus
• What does limited resolution in light microscopes mean?

  The image is blurred, preventing fine detail from being seen
• Why was the electron microscope invented?

  To explore structures inside cells in detail
• What are the key advantages of electron microscopes over light microscopes?

  They have much greater magnification and resolution
• What can be seen in the nucleus using an electron microscope that cannot be seen with a light microscope?

  Detail in the nucleus
• How do you calculate the magnification of a microscope?

  Magnification = size of the image / size of the real object
• What will you be given in the exam regarding magnification calculations?

  You will be given the equation for magnification
• If the size of the image of the nucleus is 45 mm and the real diameter is 0.01 mm, what is the magnification?

  The magnification is 4,500 times
• If the length of the real mitochondrion is 0.3 mm and the image size is 30 mm, what is the magnification?

  The magnification is 10,000 times
• How do you calculate the size of the real object if you know the image size and magnification?

  Size of the real object = size of the image / magnification
• If the size of the image is 87 mm and the magnification is 2,000 times, what is the size of the real cell?

  The size of the real cell is 0.435 mm
• What are the main differences between light microscopes and electron microscopes?

  • Light microscopes have limited magnification and resolution.
  • Electron microscopes have much greater magnification and resolution.
  • Light microscopes use visible light, while electron microscopes use electron beams.
• What steps should you follow to calculate magnification?

  1. Measure the size of the image.
  2. Measure the size of the real object.
  3. Use the formula: Magnification = size of the image / size of the real object.
• What are the limitations of light microscopes?

  • Limited magnification prevents viewing small structures.
  • Limited resolution results in blurred images.
• What can be observed with an electron microscope that is not visible with a light microscope?

  • Fine details within the nucleus and other cellular structures.