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Cell Discovery & Cell Theory

Cell Discovery & Cell Theory. It all started with an invention…. The first microscope Zacharias Jansen, 1595, Middleburg, Holland It launched great leaps in Astronomy and Biology. Some of the first great observations with it were made by…. Designed microscopes Discovered and documented

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Cell Discovery & Cell Theory

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  1. Cell Discovery & Cell Theory

  2. It all started with an invention…. • The first microscope • Zacharias Jansen, 1595, Middleburg, Holland • It launched great leaps in Astronomy and Biology. • Some of the first great observations with it were made by…

  3. Designed microscopes • Discovered and documented the first “cells” in 1665 • Named them after the cells in which a monk sleeps. Robert Hooke (1635-1703)

  4. Released book of detailed drawings and observations: Micrographia, 1665 Drawing of Flea Hooke had a life-long rivalry with Sir Isaac Newton. Newton worked hard to destroy his reputation during and after his death. Much of Hooke’s work was destroyed – even his gravesite is still unknown. Robert Hooke (1635-1703)

  5. Images from Micrographia

  6. Images from Micrographia

  7. Images from Micrographia

  8. A tradesman from Holland who became fascinated with Hooke’s book • Discovered bacteria, protists, sperm cells, blood cells, nematodes, etc. • Became an expert lens grinder and made over 500 simple microscopes • Acute eyesight and lens grinding skill let him build microscopes that were capable of 200X magnification Antony van Leeuwenhoek (1632-1723)

  9. 1838 MattiasSchleidenstated that all plant tissues consisted of cells • 1839 Theodore Schwannstated that all animal tissues consisted of cells • Each conjectured that there was a nucleus • 1858 Rudolf Virchow combined the two ideas and added that all cells come from pre-existing cells, formulating the Cell Theory Cell Theory

  10. Rudolf Virchow1858 Cell Theory • All living things are composed of one or more cells • In organisms, cells are the basic units of structure and function. • All cells are produced only from existing cells.

  11. Some of the light microscopes here are capable of 1000x magnification. • That is about the limit of a light microscope’s magnification without losing clarity (called Resolving Power). • Due to the width of visible light’s wavelength • The electron microscope was introduced in the 1950s and uses the wavelength of electrons to increase the resolving power by 100x. • Approx. 100,000x magnification!! • Cell Biology advanced rapidly as cellular organelles were clearly seen for the first time. Modern Microscopes

  12. Resolving Power

  13. Modern Microscopes Scanning Electron Microscope (SEM) shows 3D image of the Rabbit trachea cilia Transmission Electron Microscope (TEM) magnifies a slice of a sample. (Rabbit trachea cilia)

  14. Specimen must be placed in a vacuum and is typically coated with a conductive metal like gold. Consequently you can’t look at living specimens under electron microscopes. • All images produced are black and white, so you can’t distinguish colors. Pictures are usually colored in digitally later. A few limitations of electron microscopes

  15. http://www.telegraph.co.uk/science/picture-galleries/7924099/Creepy-crawlies-Amazing-Scanning-Electron-Microscope-pictures-of-insects-and-spiders.htmlhttp://www.telegraph.co.uk/science/picture-galleries/7924099/Creepy-crawlies-Amazing-Scanning-Electron-Microscope-pictures-of-insects-and-spiders.html Other Cool SEM pictures

  16. Carbon atoms bonded to hydrogen

  17. Fruit fly with four eyes under an SEM

  18. Jansen Light Microscope Hooke Electron Microscope Van Leeuwenhoek Schleiden Schwann Virchow Cell Theory Resolving Power Vocabulary: Cell History

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