Microscopes

• Light microscope


  Works by allowing light to pass through the specimen and then through the magnifying lenses
• Electron microscope


  Works by allowing a beam of electrons to pass through the specimen to build up an image on a computer
• The light microscope and electron microscope are used to magnify specimens and allow us to study different parts of a specimen
• Light microscope

  • Starts with lowest magnification
  • Has 3 different lenses to magnify image
  • Magnification of x5 or x100
  • Stage where you can put the specimen to observe
• Electron microscope


  • Magnification of x2,000,000
  • Resolution of 0.0000002 mm
• Robert Hooke invented the microscope and discovered 'cells'


  1635-1703
• Antonie van Leeuwenhoek found a better way to make much better lenses and used these to construct a microscope with single lenses


  1632-1723
• Magnification


  How much bigger the specimen appears under the microscope
• Specimen- object being viewed under microscope
• Example of stains 


  • Lodene
• Measurement units


  • cm-mm x10
  • mm-μm x1000
  • Um-nm x1000
  • Nm-pm x1000
• Magnification increases


  Specimen appears larger
• Magnification decreases


  Specimen appears smaller
• Resolution is the smallest distance between 2 points that can still be seen
• Stains are dyes that are used to see different parts of a specimen