2. I. Why Study Cells? A. Body is made up of cells: 1. RBC 2. Nerve Cells 3. Skin Cells 4. Muscle Cells

3. B. Some more examples 5. White Blood Cells 6. T Cells & B Cells 7. Reproductive Cells 8. Stem Cells

4. C. Certain Cells can make us sick Bacterial Cells Cancer Cells Protists

5. II. History of Cell Biology 1. Zacharias Janssen A. 1595 – invented 1 st optical compound microscope

6. 2. Robert Hooke A. 1665 – used a light microscope to look at non-living cork cells

7. 3. Anton van Leeuwenhoek A. Made microscopes with magnification 10x greater B. Observed living cells

8. IV. Cell Theory A. 150 years later….(early 1800’s) B. Three German scientists developed a theory about cells from their observations.

9. CELL THEORY 1.) All living organisms are composed of one or more cells 2.) Cells are the basic units of structure and function in an organism. 3.) Cells come only from the reproduction of existing cells.

10. V. Microscopes

11. A. COMPOUND MICROSCOPE

12. B. STEREOMICROSCOPE Gives 3D images of specimen

14. C. SCANNING ELECTRON MICROSCOPE (SEM) 1. Uses electrons instead of light to project surface image of specimen

15. D. TRANSMISSION ELECTRON MICROSCOPE (TEM) 1. Works like light microscope except uses electrons

16. Electron Microscopes 2. Can magnify up to 200,000 x