Microscopes Flashcards

3.2.1.3

You may prefer our related Brainscape-certified flashcards:
1
Q

Define magnification

A

Magnification is how much bigger a sample appears to be under the microscope than it is in real life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define resolution

A

The minimum distance apart that 2 objects can be in order for them to appear as separate items (the absolute to distinguish between two points on an image)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe a light microscope

A
  • uses a beam of light focused by a glass lenses
  • light has a longer wavelength than electrons so light microscope has lower resolution than electron microscopes
  • light penetrates sample
  • specimen needs to be thin (1 cell)
  • 2D image
  • Image seen in colour due to stain
  • living specimen can be viewed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe a TEM microscope.

A
  • uses a beam of electrons focused by electromagnets
  • elections have a shorter wavelength than light so TEM has higher resolution than light microscope
  • electrons penetrate sample
  • specimen needs to be extremely thin
  • 2D image
  • Image seen in black and white
  • in a vacuum so can’t view live specimen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe a SEM microscope

A
  • uses a beam of electrons focused by electromagnets
  • electrons have shorter wavelength than light so SEM has higher resolution than light microscope
  • electrons bounce off the surface of the sample
  • 3D image
  • image seen in black and white
  • in a vacuum so no live specimens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you prepare a slide for a microscope? (Light microscope)

A
  • thin, often 1 cell thick so light can pass through
  • stained so you can distinguish between different components
  • sample is placed on slide with a drop of water so the sample doesn’t dry out
  • cover slip on top, lowered with a mounted needle to prevent bubbles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly