1
Q
What is the resolution and magnifications of a light telescope?
A
- 200 nm
- x1500/ 2000
2
Q
What is the resolution and magnification of a transmission electron microscope?
A
- 0.2 nm
- x 500,000
3
Q
What is the resolution and magnification of a scanning electron microscope?
A
- 3-10nm
- x 250,000
4
Q
What is ‘resolving power’?
A
- degree at which detail can be seen in a microscope
- reciprocal to the wavelength
- shorter the wavelength, greater the resolution.
5
Q
The use of ‘stains’ in microscopy. (3)
A
- gives contrasts between certain structures
- combines with certain chemical structures
- makes certain structures visible
6
Q
Examples of stains that bind to certain chemical properties…
A
- Iodine solution; starch; turns blue/ black
- Eosin solution; cytoplasm; turns pink
- Feulgens agent/ Aceto- orcein agent; DNA; dark red/ purple
7
Q
Resolution is…
A
The ability of an optical system to distinguish between two adjacent objects
8
Q
Light microscope
A
- light source and lense
- light bounces of material into lense that focuses to produce magnified image
9
Q
Transmission electron
A
- electron through sample, then detected to form image
- 2D image
10
Q
Scanning electron
A
- electrons bounce off sample
- detector forms image shown on screen
- 3D image
