Microscopes Flashcards
1
Q
What is magnification?
A
The factor by which an image has been enlarged.
2
Q
What is resolution?
A
The ability to see closely placed objects as separate structures.
3
Q
What are the key features of a light microscope?
A
- specimens are illuminated with light.
- specimens can be living or dead.
- often need to be stained to be visible and to be thin.
- Use several lenses to obtain a high magnification.
4
Q
What are the key features of TEM’s?
A
- Produces a beam of electrons which form an image on a screen.
- uses a dead specimen.
-Uses very thin specimens. - Produces black and white images
- produces 2D images.
- shows the inside of structures.
5
Q
What are the key features of SEM’s?
A
- Scans a fine beam of electrons onto a specimen and collects the electrons scattered
- Has the best resolution
- Shows the surface of cells
- Dead samples
- Produces coloured images
- Produces 3D images