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What are the types of microorganisms?
- Prokaryotic(Simple design, no nucleus): Bacteria, Archaea
- Eukaryotic(Complex design, contains nucleus): Fungi, Protozoa, Algae
- Viruses: Tiny, not cellular
Describe Antoni van Leeuwenhoek's idea of spontaneous generation
That living organisms can be made from dead organisms
What was the purpose of Pasteur's experiment?
The idea was to boil broth in a flask with a curved neck where no oxygen can enter. However it remained clear showing that nothing grew from it. Showing that life only comes from life.
What is resolution
- Also known as resolving power.
- Resolving power= wavelength/ 2*NA
What is Numerical Aperature?
It is the function of the lens size and the refractive index of the medium the light travels through. ex) Air and water bend light rays differently. ex) displaced looking straw on glass of water
What is the purpose of an oil immersion lens?
It has a small diameter and we increase the gathered light rays by putting oil between the glass slide and glass lens. The oild has the same refractive index as glass
Describe each type of microscope and the advantages/disadvantages of each.
- Brightfield(ours): Least expensive. Shows the internal structures and the outline of the transparent pellicle.
- Darkfield: (no color)enhances outlines, dont need to stain.
- Phase contrast: Best detail of internal structures
- Flourescence: Hightlight specific objects (glow in the dark). Shows greater differentiation of internal structures and clearly shows the pellicle.
- Electron microscope disadvantage- specimens are under vacuum which means they're dead. Staining or spraying with dense metals improves contrast, but artifacts can be created
What is staining?
It increases the contrast by changing the refractive index. First must fix specimen to slide, usually by heat.
What types of stains are there?
- Simple: All cells are stained one color
- Differential: Distinguishes types in two colors
- Special: Highlights a particular structure