Karteikarten
Microscopes
Karten in diesem Stapel (24)
- 1Define magnificationA measurement of the number of times larger an image is compared to its actual size
Magnification = Image size / Object size - 2How many mm are there in one nanometer (nm)?0.000001 mm
- 3How many mm are there in one micrometer (µm)?0.001 mm
- 4Define resolutionHow detailed the image is.
Specifically, how well a microscope distinguishes between two points that are close together - 5What are the 3 types of microscope?Light microscope
Laser scanning confocal microscope
Electron microscope - 6What are the two types of electron microscope?Transmission electron microscope (TEM)
Scanning electron microscope (SEM) - 7What are the properties of light microscopes?Uses light
Lower resolution than electron microscope
Usually used to look at whole cells/tissues
Maximum magnification = x1500
Maximum resolution = 0.2 µm - 8What are the properties of laser scanning confocal microscopes?Uses laser beams to scan a specimen that is tagged with fluorescent dyes
Can be used to look at objects at different depths in thick specimens
Multiple images can be combined by the computer to generate 3D images - 9How does a laser confocal microscope produce an image?1. A laser beam is focused through a lens which is aimed at a beam splitter
2. This splits the beam and some of the light is directed to the specimen
3. This light is then focused through a pinhole onto a detector
4. The pinhole means that any out-of-focus light is blocked, producing a much clearer image than a normal light microscope
5. The detector is hoked up to a computer, which generates an image - 10What are the properties of electron microscopes?Uses electrons instead of light
Have a higher resolution so give more detailed images - 11What are the properties of transmission electron microscopes (TEMs)?Uses electromagnets to focus a beam of electrons, which is then transmitted from the specimen to produce 2D images
Denser parts of the specimen absorb more electrons, making it look more darker on the image
Provides high resolution images to look at very small organelles
Used to look at the internal structures of organelles in detail
Specimens viewed must be thinly sliced - 12What type of electron microscope generated this image?Transmission electron microscope (TEM)
- 13What are the properties of scanning electron microscopes (SEMs)?Scan a beam of electrons across the specimen
This knocks off electrons from the specimen, which are gathered in a cathode ray tube to form an image
The images produced show the surface of the specimen and can be 3D
Gives lower resolution images than TEMs - 14What type of electron microscope generated this image?Scanning electron microscope (SEM)
- 15What is the maximum resolution and magnification of a light microscope?LIGHT MICROSCOPE
Resolution = 0.2 µm
Magnification = x1500 - 16What is the maximum resolution and magnification of a TEM?TEM
Resolution = 0.0002 µm
Magnification = Can be > x1,000,000 - 17What is the maximum resolution and magnification of a SEM?SEM
Resolution = 0.003 µm
Magnification = Usually < x500,000 - 18Name 2 stains commonly used in light microscopyMethylene blue
Eosin - 19How does staining work?The stain is taken up by some parts of the object more than others, meaning that some parts become more heavily stained than others.
The contrast between heavily stained and lightly stained parts means that different parts of cells can be seen. - 20What type of cell does methylene blue stain?DNA
(Above = cheek cell stained)
- 21What types of cells do Giemsa stain differentiate?Commonly used to differentiate between different types of blood cells
(Above = blood smear stained)
- 22Outline the process of using a light microscope (dry mount)1. Use tweezers to pick up your specimen and put it into the middle of a clean slide
2. Pop a cover slip on top - 23Outline the process of using a light microscope (wet mount)1. Pipette a small drop of the liquid onto the slide
2. Use tweezers to place the specimen on top of the drop
3. To put a cover slip on, stand the slip upright on the slide, next to the droplet
4. Carefully tilt and lower the slip so it covers the specimen (try not to get air bubbles underneath)
5. Once the cover slip is in position, you can add a stain. Put a drop of stain next to one edge of the cover slip and put a bit of paper towel next to the opposite edge
6. The stain will get drawn under the slip, across the specimen - 24How is an eyepiece graticule and stage micrometer used?An eyepiece graticule (a transparent ruler with numbers, but no units) is fitted onto the eyepiece.
The stage micrometer is placed on the stage - it is a microscopic slide with an accurate scale (it has units) and is used to work out the value of the divisions on the eyepiece graticule at a particular magnification.
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- Beschreibung
- Der Nutzer hat seine Fachbereichs-Information gelöscht. Karteikarten am Microscopes, erstellt von Gelöschter Nutzer am 05/03/2018.
- Erstellt von
- Gelöschter Nutzer · Mär 2018
- Aktualisiert
- 5 Mär 2018
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- 178
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- Erstellt von Yinka F · 22 Jan 2018
- Kopiert von Yinka F · 5 Mär 2018
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