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Download contributions to the cell theory
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CONTRIBUTIONS TO THE CELL THEORY Timeline of scientists and their discoveries 1) Anton von Leeuwenhoek 1600’s Dutch businessman Invented 1st simple light microscope Anton von Leeuwenhoek (con’t) Observed tiny organisms in pond water Organisms were nicknamed “wee beasties” 2) ROBERT HOOKE 1665 English physicist Observed flowers, insects, and plant tissue ROBERT HOOKE (con’t) Observed thin slices of cork (oak tree) Coined the term “cell” based on the rooms in a monastary 3) ROBERT BROWN 1833 Observed plant cells under the microscope ROBERT BROWN (con’t) Observed a dark structure inside each cell and coined the term “nucleus” 4) MATTHIAS SCHLEIDEN 1838 German botanist: scientist who studies plants Concluded all plants are made up of cells 5) THEODORE SCHWANN 1839 German biologist Concluded all animals are made of cells 6) RUDOLF VIRCHOW 1855 German Physician Studied cell reproduction Concluded all cells arise from preexisting cells The cell theory 1. All living things are composed of cells 2. Cells are the basic unit of structure and function in living things. 3. All cells arise from preexisting cells. Introduction to Cells Chapter 6 Levels of Organization All living organisms can be studied on many levels From smallest to largest they are: Chemical (atoms & molecules) Cells Tissues Organs Organ Systems Whole Organism Basic Structure of Cells All cells have a cell membrane and cytoplasm Cell Membrane: thin, flexible barrier around cell Composed of lipids and proteins Cytoplasm: jelly-like material inside the cell All cells contain organelles Organelles: small structures that perform different functions within a cell Prokaryotic Cells Do NOT have a nucleus Instead a small ring of DNA is free-floating in center of cell Organelles do NOT have a membrane i.e.: bacteria (very simple organisms) Eukaryotic Cells Contain a nucleus Organelles are membrane-bound Much more complex i.e.: plants, animals, fungi
