1. Cell Theory

2. Cell theory states: 1.All living organisms are composed of cells. They may be unicellular or multicellular. Unicellular = single cell organisms Multicellular = organisms made up of more than one cell http://www.infovisual.info/02/003_en.ht ml

3. Cell Theory 2. The cell is the basic unit of structure and function. 3. All cells come from previously existing cells. Exceptions: ____________________________

4. Cell Theory Timeline 1665 - Robert Hooke of England looks through a microscope at a sliver of cork. He notices what he calls cells. He is the first person to use the word cell to describe microscopic structures. http://images.tutorvista.com/content/cell-unit- life/scientist-robert-hooke.jpeg

5. Cell Theory Timeline 1674 - Anton Van Leeuwenhoek, of Holland, used microscopes to view many things including pond organisms, bacteria and blood cells. He made careful sketches of what he observed. http://fiskims.edublogs.org/files/2009/09/Leeuwenhoek.JPG Listed number 1 on the Science Channel’s 100 Greatest Discoveries

6. Cell Theory Timeline 1831 - Robert Brown discovers the nucleus of the cell. He stresses its importance in fertilization. http://www.xtimeline.com/__UserPic_Large/108226/evt110424021800176.jpg http://science.discovery.com/convergenc e/100discoveries/big100/biology.html Listed number 2 on the Science Channel’s 100 Greatest Discoveries

7. Cell Theory Timeline 1839 - Matthias Schleiden and Theodor Schwann create cell theory. The theory states that all living things are made up of one or more cells. Schleiden publishes his cell theory applying it to plants, while Schwann publishes his applied to animals.

8. Cell Theory Timeline 1855 - Rudolf Virchow writes and publishes his aphorism omnis cellula e cellula, which means every cell stems from another cell. He theorizes that all forms of disease come from changes in normal cells. http://www.pathguy.com/virchow5.jpg