Cell Theory a unifying theory that describes all

Cell Theory: a unifying theory that describes all cells 1. All living things(organisms) are composed of cells 2. Cells are the basic units of structure and function for living things. 3. All cells come from previously existing cells.

Modern Cell Theory 4. The activity of an organism depends on the total activity of independent cells. 5. Energy flow occurs within cells. 6. Cells contain hereditary information(DNA), which is passed from cell to cell during cell division. 7. All cells are basically the same in chemical composition in organisms of similar species.

Cell Membrane Homeostasis: in living things the maintenance of a stable internal environment, as a response to a changing external environment How does the cell membrane regulate homeostasis? the cell membrane only allows certain substances to cross it. The internal cell environment will stay stable.

Cell Size As a cell gets larger, the surface area of the cell membrane is no longer large enough to allow for the efficient. . 1. removal of wastes 2. acquisition of food

Effect of solution Concentration on Animal & Plant Cells plasmolysis: when plant cells are placed in a hypertonic solution, and the cell membrane shrinks away from the cell wall. cytolysis: when animal cells are placed in a hypotonic solution, and take in enough water to burst. turgor: water pressure inside a plant cell causes the cell membrane to press against the cell wall turgid= in hypotonic solutions the plant cells are rigid flaccid= in isotonic solutions cells are wilted plasmolyzed= in hypertonic solutions cells are permanently wilted