2.1.3: Methods of studying cells Flashcards
1
Q
Describe magnification
A
How many times larger is compared to actual size of objects
2
Q
Describe resolution
A
Ability to distinguish two objects that are close together
3
Q
Principles of optical microscopes
A
- beam of light focused on lens to create an image
- Longer wavelength of light so lower resolution
4
Q
Limitation of optical microscope
A
- Lower resolution
- Lower magnification
5
Q
Principles of TEM
A
- Electrons pass through specimen
- Denser parts absorb more electrons
- Denser parts appear darker
- Electrons have short wavelength so have high resolution
6
Q
Limitation of TEM (4)
A
- Cant look at living material
- Specimen must be thin
- Artefacts present
- Complex staining method
7
Q
Advantages of SEM (3)
A
- Sections do not need to be prepared
- Shows surface of specimen
- 3D images
8
Q
A
