1. Ch 3 S1: The Diversity of Cells

2. What is a cell?  A cell is the smallest unit that can perform all the processes necessary for life.

3. What is the cell theory?  The cell is the basic unit of structure & function in all living things.  All organisms are composed of one or more cells.  All cells come from other cells.

4. Important Scientists and their Contributions Robert Hooke First to see cells Anton van Leeuwenhoek First to see protists, which he called animalcules, and bacteria. Matthias Schleiden Concluded that plant parts were composed of cells. Theodor Schwann Worked with Schleiden Concluded that animal tissues were composed of cells. Rudolph Virchow Concluded that cells could only come from other cells

5. Cell Size  Cells, like a chicken egg, can be large because they do not have to take in nutrients.  Most cells are small because they must take in food and get rid of wastes.  The area of a cell’s surface compared to its volume limits the cell’s size.

6. Parts of a Cell  All cells have some parts in common. These parts are called organelles.  Cell Membrane: protective layer that covers the cell’s surface and acts as a barrier.  Cytoplasm: the fluid inside a cell  Organelles: structures that perform specific functions within a cell.  DNA: controls the activities of a cell; may be enclosed in the nucleus or free-floating

7. Two Kinds of Cells Eukaryote  Single-cellular or multicellular organism whose cells that DO have a nucleus Prokaryote  Single-celled organism that lacks membrane bound organelles and a nucleus  PRO means NO (nucleus)!!!

8. Prokaryotes: Bacteria & Archaea  Bacteria are the most common prokaryotes  Three types of Archaea  heat-loving  salt-loving  methane-making  heat-loving and salt-loving are called extremophiles  extremophiles are organisms that live in extreme conditions

9. Eukaryotes  Eukaryotic cells are the largest cells and are 10 times larger than most bacterial cells  Have a Nucleus  Most Eukaryotes are multicellular  ex: humans, plants, fungi