1. Pamela Nell Copyright 2004 CELLS: The Units of Life Mrs. Nell 7 th Grade Life Science

2. Pamela Nell Copyright 2004 Overview CELLS: The Units of Life Early Microscopes The First Microscope Cell Discovery Development of the Cell Theory Development of the Cell Theory (II) Development of the Cell Theory (III) The Cell Theory Microscopes Today (I) Microscopes Today (II) Microscopes Today (III) Types of Electron Microscopes

3. Pamela Nell Copyright 2004 Early Microscopes Simple (one lens) Compound Zacharias Janssen 1590 Created first compound microscope by putting two magnifying glasses together

4. Pamela Nell Copyright 2004 The First Microscope Anton Van Leeuwenhoek 1600’s Created a simple microscope using a tiny glass bead for a lens which magnified 270x.

5. Pamela Nell Copyright 2004 Cell Discovery Cells weren’t discovered until microscopes were improved. Robert Hooke 1665 Sliced a cork and studied it under his microscope Noted that cork was made of ‘little boxes’ which he called cells (actually cell walls of the cork plant) Cork cells

6. Pamela Nell Copyright 2004 Development of the Cell Theory Matthias Schleiden (German Scientist) 1838 Used microscope to study plant parts Concluded all plants are made of cells

7. Pamela Nell Copyright 2004 Development of the Cell Theory (II) Theodor Schwann (German Scientist) 1839 Observed many animal cells Concluded animals are made of cells

8. Pamela Nell Copyright 2004 Development of the Cell Theory (III) Rudolph Virchow (German Doctor) 1854 Hypothesized cells divide to form new cells One of first to challenge the ‘Spontaneous Generation’ Theory (theory that life happens spontaneously from nonliving matter)

9. Pamela Nell Copyright 2004 The Cell Theory The observations/conclusions of many scientists became known as the ‘Cell Theory’. 1) All organisms are made up of 1 or more cells 2) Cells are the basic units of structure and function in all organisms 3) All cells come from cells that already exist

10. Pamela Nell Copyright 2004 Microscopes Today (I) Compound Light Microscope Light passes through object then through 2 or more lenses Eyepiece lens 10x Objective lens 43x Total magnification 430x

11. Pamela Nell Copyright 2004 Microscopes Today (II) Stereo Light Microscope (Stereoscopic) 3-D view Objective/Ocular for each eye To look at thick structures light can’t pass through (ex.- insects, leaves, etc.)

12. Pamela Nell Copyright 2004 Microscopes Today (III) Electron Microscope For objects too small to be seen with light microscope Uses magnetic field to bend beams of electrons Can magnify 1,000,000x Mosquito image as seen through Scanning Electron Microscope

13. Pamela Nell Copyright 2004 Types of Electron Microscopes Transmission (TEM) (Transmission Electron Microscope) Used to study parts inside a cell Object has to be sliced thin and placed in a vacuum Only dead cells/tissues can be observed this way Scanning Electron (SEM) (Scanning Electron Microscope) Used to see surfaces of whole objects Can view/photograph living cells

14. Pamela Nell Copyright 2004 Bibliography Microscope. [Online image] Available http://www.hc-sc.gc.ca/ear-ree/pres_environ_impact_init_e.html, July 2004.http://www.hc-sc.gc.ca/ear-ree/pres_environ_impact_init_e.html Zacharias Janssen. [Online image] Available http://microscopy.fsu.edu/optics/timeline/people/antiqueimages/janssen.jpg, July 2004. http://microscopy.fsu.edu/optics/timeline/people/antiqueimages/janssen.jpg Anton Van Leeuwenhoek. [Online image] Available www.okscienceproject.org/ scientists/anton.htm, July 2004.www.okscienceproject.org/ scientists/anton.htm Robert Hooke. [Online image] Available iesfelanitx.webcindario.com/ cientifics_menu.htmiesfelanitx.webcindario.com/ cientifics_menu.htm Cork Cells. [Online image] Availabe biology.clc.uc.edu/.../ Cell_Biology/Cells_Lab/, July 2004.biology.clc.uc.edu/.../ Cell_Biology/Cells_Lab/ Matthias Schleiden. [Online image] Available home.tiscalinet.ch/.../ biografien/schleiden.htm, July 2004.home.tiscalinet.ch/.../ biografien/schleiden.htm Theodor Schwann. [Online image] Available home.tiscalinet.ch/.../ biografien/schwann.htm, July 2004.home.tiscalinet.ch/.../ biografien/schwann.htm Rudolf Virchow. [Online image] Available http://home.tiscalinet.ch/biografien/biografien/virchow.htm, July 2004.http://home.tiscalinet.ch/biografien/biografien/virchow.htm Compound Light Microscope. [Online image] Available www.cas.muohio.edu/.../ compoundscope.html, July 2004.www.cas.muohio.edu/.../ compoundscope.html Stereo Light Microscope. [Online image] Available www.montreal-biotech.com/ Uni7.html, July 2004.www.montreal-biotech.com/ Uni7.html Scanning Electron Microscope. [Online image] Available www.hitachi-hitec.com/.../ product/tem/h7500.html, July 2004.www.hitachi-hitec.com/.../ product/tem/h7500.html Transmission Electron Microscope. Online image] Available www.hitachi-hitec.com/.../ product/tem/h9500.html, July 2004.www.hitachi-hitec.com/.../ product/tem/h9500.html