Topic: Discovering Cells Date: 10/21/14 Page #: 45 EQ: What are cells?

O Overview of Cells: 1.Cells are the basic units of structure and function in living things 2.Very small -measured in micrometers 3.Cells form the parts of an organism and help your body function

Invention of the Microscope 1663: Robert Hooke sees cells in cork. Anton van Leeuwenhoek uses simple microscope to observe animalcules. 1838: Mathias Schleiden concludes that plants are made of cells. 1839: Theodor Schwann concludes that animals are made of cells.

1855: Rudoph Virchow proposes that cells come from existing cells. Schleiden, Schwann & Virchow develop Schleiden, Schwann & Virchow develop Cell Theory. Cell Theory.

T The Cell Theory: 1.All living things are composed of cells. 2.Cells are the basic units of structure and function in living things. 3.All cells are produced from other cells.

Unicellular and Multicellular Unicellular and Multicellular UnicellularMulticellular  organisms that are composed of only one cell  Ex. Bacteria  organisms that are composed of many cells  MORE COMPLEX  Ex. All other cells- plants, animals, fungus

M Multicellular Organisms: 1.In multicellular organisms, cells are organized into tissues, organs, and organ systems OrganSystemCellsTissueOrgan

Complete on p. Use COLOR and RULERS Cells Tissue Organ Organ System

Biological Levels of Organization List on page 44 in spiral.