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Download 7.1 Cell Discovery and Theory
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7.1 Cell Discovery and Theory Discovery of the Cell 1665 - Robert Hooke identified cells in cork and named them Cell Discovery & Theory Section 7.1 Hooke 1683 - Anton van Leeuvenhoek 1st to describe living cells 1838 - Matthias Schleiden proposed plants were made of cells Leeuvenhoek 1839 - Theodor Schwann concluded all living things are made of cells Schwann Virchow 1855 - Rudolf Virchow proposed all cells come from existing cells Schleiden Cell Theory 1. all organisms are made of cells 2. all existing cells are produced by other living cells 3. the cell is the most basic unit of life Cells in General · · · · vary in size and shape tend to be microscopic enclosed in a membrane filled with cytoplasm jellylike substance that contains dissolved molecular building blocks (proteins, nucleic acids, minerals, ions) · some cells have organelles structures that perform a specific task in the cell Prokaryotic Cells · NO nucleus · NO membrane-bound organelles · single-celled Eukaryotic Cells · have a nucleus (houses genetic material - DNA) · have membrane-bound organelles · multicellular or single-celled 7.1 Cell Discovery and Theory M i c r o s c o p e s · compound light microscope uses lenses and light to magnify objects max magnification = 1000x ocular (eyepiece) x lens = total magnification often uses stains to see cells better · electron microscope transmission electron microscope (TEM) uses magnets to aim a beam of electrons through cells max magnification = 500,000x specimen must be dead, sliced very thin, and stained with heavy metals
