1. Cell Theory And its exceptions

2. Background Invention of microscope by van Leeuwenhoek 1665 – Robert Hooke – Viewed cork – saw cell walls – Named them “Cells” Robert Brown – Saw large dark staining structure in middle of cells – Named the “nucleus”

3. Cell Theory – 3 parts 1. Living things are made of cells 2. Cells are the basic unit of structure and function of living things – Schleiden worked with plants – Schwann worked with animals 3. Cells come from other cells – Virchow saw cells dividing under the microscope

4. Exceptions 1.If ALL cells come from other cells – where did the first cell come from?????????????? 2.What about viruses???? -Not made of cells -Don’t do GRRSNERT -NOT living

5. Last Exception 3. Mitochondria and Chloroplasts - Have their own DNA (separate from nucleus) -Can reproduce independently from the rest of the cell -Did they once live on their own????

6. Cells Vary in Shape because they vary in Function – made of different proteins

7. Why are Cells small? Smaller is more efficient Larger requires more ENERGY