Term
| 1. How does a simple microscope differ from a compound microscope? |
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Definition
| A simple microscope has only one lens and can magnify an object up to 15 times the object's size. A compound microscope has two lenses and can magnify an object more than 2,000 times. |
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Term
| 2. Define: magnification, resolution(resolving power), and refraction. What determines the resolving power of a light microscope? |
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Definition
Magnification-The process of enlarging the size of something, as an optical image.Something that has been magnified; an enlarged representation, image, or model.
Resolution(Resolving power)-A measure of the smallest separation at which a telescope can observe two neighboring objects as two separate objects.defines the capacity of an optical system to ditinguish two adjacent objects or points from one another.
Refraction-is the change in direction of a wave due to a change in its speed. This is most commonly observed when a wave passes from one medium to another at any angle other than 90° or 0°. Refraction of light is the most commonly observed phenomenon. |
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Term
| 3. For what special application might a dark field microscope be used? |
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Definition
Best for observing live, unstained specimens; specimen is brigh, field is black; provides outline of specimen with reduced internal cellular detail.
visualize living cells that would be distorted by drying or heat, or cannot be stained with the usual methods |
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Term
| 4. Why must specimens be stained for brightfield microscopy? |
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Definition
| the speciman being denser and more opaque than its surroundings, absorbs some of this light. |
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5. How do electron microscopes differ from light microscopes in regards
to focusing and illumination? |
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Definition
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6. Name two types of electron microscopes and how their applications
differ. |
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Definition
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Term
| 7. What type of microscope is needed to study viruses? |
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Definition
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Term
8. In the negative staining technique, the cell or cell part does not
absorb the dye but remains colorless. Is that a true statement? |
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Definition
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Term
| 9. For what is the hanging drop procedure used? |
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Definition
a hanging drop is used to observe living microorganisms under the microscope
it consists of a slide with a cavity over which a drop of medium is suspended from a cover slip
it provides a true assessment of the size, shape, arrangement, color, and motility of the cells. |
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Term
10. The most important stain technique in microbiology is?
Describe the mechanism of this technique. |
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Definition
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Term
| 11. The bacterial cell has what kind of electrical charge on its surface? |
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Definition
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12. Why do acid-fast organisms need a different kind of staining
procedure? |
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Definition
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Term
| 13. How do differential stains differ from simple stains? |
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Definition
| Simple stains require one single dye & help to stain the outlines of bacterial cells, giving one the characteristic shape, size, and arrangments of the cells stained with the simple stain.Using a differential stain uses 2 different-colored dyes, called primary dye and counterstain. such as the basic dye; Crystal Violet, helps to firstly visualise both cell types purple. |
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