1. Cell theory notes

3. The Cell Theory Robert Hooke- (1665) examined a piece of cork under a microscope and discovered cells. Schleiden (1873) concluded that all plants are composed of cells and that cells are the basis of all its functions.

4. The Cell Theory Theodor Schwann- (1839) “concluded that all animals are composed of cells and that they are the basis behind all of their functions” Rudolf Virchow- (1858) “stated that all cells come from other living cells.”

5. Cell Theory 1. All organisms are composed of one or more cells or cell fragments. 2. The cell is the basic unit of structure and function in organisms 3. All cells are produced from other cells. Memorize this !!!

6. Cell Types 1. Prokaryotic Cells- –Cells that do not have a true nucleus. (they still have DNA) –Most are bacteria –All are unicellular 2. Eukaryotic Cells- –Cells that contain a membrane bound nucleus and membrane bound organelles. –Can be multi or unicellular –This includes most living things (Plants and animals)

7. Plant cells vs. Animal cells Plant cells (usually brick shaped) –Have thick cell wall made of cellulose. –Possess large vacuoles for storage of water. –Contain chloroplasts (photosynthesis) Animal cells (not green) –Animal cells lack those structures found above. –Animal cells usually are not brick shaped.