investigating cells

• typical size of a plant cell

  0.1mm
• typical size of an animal cell

  0.02mm
• typical size of a prokaryotic cell

  0.002mm
• PREFIXES

  • centimetre (100)
  • millimetre (1000)
  • micrometre (1000000)
  • nanometre (1000000000)
• WHEN was the light microscope developed?

  late 16th century
• light microscope

  • gave a GREATER RESOLUTION than the eye
  • allowed people to see PLANT, ANIMAL and BACTERIA cells
• what could you not see with the light microscope?

  sub cellular structures
• WHEN was the first electron microscope used?

  1933
• ELECTRON MICROSCOPE

  gives a much better resolution. so…

  • mitochondria, chloroplasts can be studied
  • ribosomes can be seen and protein-synthesis can be studied
• (RP!!)- MICROSCOPE

  1.place tissue sample on slide

  2.add iodine solution to stain

  3.put coverslip on top of the sample

  4.place sample onto stage

  5.focus on cells initially using low power

  6.change to high power and resolution

  7.draw the cells

  8.add scale line