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2. All organisms are made of cells
Cell Theory
Mathias Schleiden(Botanist) 1838 Theodor Schwann (Zoologist) 1838
All organisms are made of cells
Cells are the smallest unit of living things.
Cells give rise to other cells.

3. The Simple Microscope

4. Anton Von Leeweunhoeke
(1630’s)

5. Robert Hooke (1665)

6. Compound Microscope

7. Italian Compound Microscope, signed by François Baillou, Milan, c. 1700.

8. Compound
Microscope
(Modern)

10. Images
Stomata of a plant

11. Ameoba

12. Compound Microscope: Key Points
Two lenses ( ocular and objective)
The ocular magnifies the image from the objective.
*2-D images
*can use live samples
*light must pass through sample to see it
*light source needed: reflected by a mirror (old) or electric power
1000x at the most; we have 400x as the highest mag. at school.
Resolution and clarity is ok

13. Electron Microscope
First one around 1930
First

15. Two coccolithophores viewed under a scanning electron microscope
Two coccolithophores viewed under a scanning electron microscope. Top: Helicosphaera hyalina. Bottom: Discosphaera tubifera (Photos by Vita Pariente)

16. Transmission Electron (TEM)
DNA
Golgi body

18. Scanning Electron(SEM)

19. Pollen
Hookworm

20. Weevil head

22. Fern leaf cross section

23. Black Widow spider claw

24. Dentist Drill

25. Electron Microscope: Key points
Electrons as a source to view sample; image captured by computer…not light.
*very specific magnification ( 1million x)
Computer needed for precision and accuracy.

26. SEM Sample coated with a metal ion
Electrons shot over sample and scan across
Electrons bounce off the surface and provide a 3-D image
Can view whole samples

27. TEM
Samples must be thin…very thin for electrons to pass through the sample.
Can’t be used to view whole or live samples
Very good clarity and resolution
1 million x
2-D images; very very detailed