1. Diversity of Cellular life (7-4)
The diversity of life is so great that you might have to remind yourself that all living things are composed of cells, use the same basic chemistry, follow the same genetic code, and even contain the same kinds of organelles. This does not mean that all living things are the same.

2. Characteristics of Cells
A. Come in a variety of shapes.
1. ex, cubes, bricks, spheres
B. Variety of sizes
1. ex. bacteria = smallest, ovum = biggest
C. Multicellular – many celled organism, carries out basic functions and can be specialized for certain tasks. Depend on each other for survival.
1. ex. humans, plants, animals

3. D. Unicellular – single celled organism
D. Unicellular – single celled organism. Can perform all activities of a multi-cellular organism can. Does not depend on other cells, it survives alone.
1. ex. Bacteria, amoeba

4. 2. Cell Specialization (fig. 7-21; pg. 191)
A. Cells are specialized so that certain cells can perform particular function in specific organism.
B. Red blood cells - transport oxygen.
C. Pancreatic cells -produce proteins.
D. Muscle cells – attach to skeleton and move body.
E. Guard cells around the stomata of a plant allow gas to enter and leave the leaf of a plant.

5. Voluntary smooth muscle cell
Voluntary striated muscle cell
Cardiac muscle cell

6. Red blood cell
White blood cell
Stomata

7. Egg and sperm cell

8. 3. Levels of organization in the living world
A. Cell – basis of all organisms
B. Tissue – group of cells with same structure and function working together
C. Organ – group of tissues working together to perform a complex function
D. Organ system – group of organs working together
E. Whole organism – group of organ systems working together for the complete organism