Bio 230: Cell Bio Intro to Cells: pg 1-26 Properties that define living organisms: Ability to reproduce on their own Viruses? Not living organisms but incapable of reproducing on their own Can grow and develop Require energy - metabolism Response to the environment Maintain homeostasis Contains genetic information (DNA or RNA) Composed of cells Cells are the fundamental unit of life. Invention of the light microscope led to the discovery of cells Robert Hooke Shortened telescope Many flaws, difficult to see Oil lamp with flask of water to illuminate specimen Examined cork - coined term cell Remains of cell walls after death Theodore Schwann All different species of animals were composed of cells Mathias Schleiden All different species of plants were composed of cells