Cell Biology

I. The Cell Theory
     A. All organisms are composed of one, or more cells
     B. Cells are the smalles living things
     C. All cells come from previously existing cells (most contriversial)

II.Cell Size- cells are small. As volume increases, surface are does not keep up.

III. Types of Cells
     A. Prokaryotic- "Before the kernel"- Cells that have no nucleus nor do they have any membrane-bound organelles.
            - Archebacteria and Eubacteria. Evolved first. (3.5 billion years ago)
     B. Eukaryotic- "Now the Kernel"- cells with a nucleus and organelles. ex: animals, plants, fungi, protozoans, and algaes. (1.5 billion years ago)

IV. The Endosymbiotic Theory- complex cells (eukarotic) evolved from the endocytosis of other cells and subsequent cooperation between them.
          endocytosis- one cell taking in material or other cells
            certain cells "took in" other cells that had abilities to help the host cell and a symbiotic relationship developed. 2 organelles that "fit" this theory;