Cells

• Cells


  Organisms are made up of cells. Most organisms are multicellular and have cells that are specialised to do a particular job.
• Microscopes


  Needed to study cells in detail
• Light microscope


  Compound microscope uses two lenses, the objective lens and the eyepiece, to magnify the image of a biological specimen
• Compound microscope


  • The objective lens produces a greatly-magnified image, then the eyepiece magnifies this further
• Calculating magnification of microscope

  Magnification of eyepiece × magnification of objective
• Magnification


  • ×10
  • ×4
  • ×40
• Animal cells are between 0.01 mm - 0.05 mm in size
• Plant cells are between 0.01 mm - 0.10 mm in size
• The human eye can see objects as small as around 0.05 mm
• A microscope is required to see cells in any detail