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21 Cards in this Set
- Front
- Back
- 3rd side (hint)
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who observed cork and first named "cells" in 1665
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robert hooke
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what was the magnification power of the first microscope?
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30x
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Who produced the 300x light microscope?
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antonie van leeuwenhoek
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why was progress in early cell biology slow?
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limited resolution and focus only on observation, not explanation
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2 reasons
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magnification power
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how many times the size of the specimen is enlarged
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resolution
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ability to see fine details
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what are compound microscopes and why were they important?
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two lenses. increased magnification and resolution meaning structures 1 micrometer in size could be seen
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who discovered the nucleus and where?
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robert brown in plant cells
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what is matthias schleiden known for?
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all plant tissues are made of cells
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who discovered all animal tissues are made of cells?
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thomas schwann
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in 1839, who came up with the first two statements of the cell theory?
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schwann
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who and when did the third part of the cell theory get added?
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virchow in 1855
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cell theory
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1. all organisms consist of one or more cells. 2. the cell is the basic unit of life. 3. all cells come from preexisting cells
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three strands of modern cell biology
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cytology-observation of cell structures, biochemistry-cellular function at chemical level, genetics-information flow and heredity.
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two classes of microscopes
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light and electron
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what are the main differences?
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light uses glass lenses and seen by the naked eye. electron uses electromagnetic lenses and seen on fluorescent screen or photographic film
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phase contrast microscopy
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uses a refractive index different from the medium for color. best for contrast and live cells
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fluorescence microscopy
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detects fluorescent dyes/labels to locate certain substances in the cell. can be done on live cells.
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differential interference contrast microscopy
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enhanced resolution, shadow casting effect, good view of the surface of the specimen, good for live cells
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limit of resolution
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how far apart molecules must be from each other to be seen separately, greater resolving power=smaller limit of resolution
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how is limit of resolution determined?
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wavelength of the light used divided by 2.
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