Microscopy

Question 1

Light microscopes limitation

Answer 1

Can only distinguish between objects if they are 0.2 micrometers (Mm) apart. Coloured images. Can view living samples. Poor resolution due to light having longer wavelengths.
Lower magnification.

Question 2

Electron microscope

Answer 2

Have shorter wavelengths than light microscopes, therefore has a 0.1 nanometres (Nm) distinction - high resolving power.
Black and white images. Higher magnification. Sample must be in a vacuum, therefore dead.

Question 3

Magnification

Answer 3

How zoomed in a microscope is.

Question 4

Magnification equation

Answer 4

Magnification = size of image \ size of object. M = I/O

Question 5

Resolution

Answer 5

How close objects can be whilst being able to distinguish each of them.

Question 6

Resolving power

Answer 6

The minimum distance between two points that can be separated. The smaller the resolving power, the better the resolution.

Question 7

Objection and image units should be…

Answer 7

Equal

Question 8

Magnification equation

Answer 8

Magnification = size of image/ size of object

Question 9

2 pieces of equipment used to calculate size of cells on a microscope

Answer 9

Stage micrometer (precise ruler on a slide) and eye piece graticule

Question 10

4 principles of electron microscope…

Answer 10

1. Vacuum - organism dead
2. Thin sample
3. Complex staining/preparation - training required. 4. Image contains artefacts - due to staining.

Question 11

Transmission Electron Microscope (TEM)

Answer 11

2D
0.1nm (nanometer) resolution
Must be thin specimens
Transmits through the cell.

Question 12

Scanning Electron Microscope (SEM)

Answer 12

3D
20nm resolution
Focuses on surface of cells, not through the cells.