Microscopes and Magnification

Question 1

How does a light microscope form an image?

Answer 1

Uses a beam of light

Question 2

What is the maximum magnification of a light microscope?

Answer 2

X 2000

Question 3

What are the advantages of using a light microscope?

Answer 3

Relatively cheap
Can magnify live specimens

Question 4

How does an electron microscope form an image?

Answer 4

Uses a beam of electrons

Question 5

What is the maximum magnification of an electron microscope?

Answer 5

X 2 000 000

Question 6

What are the 2 types of electron microscopes?

Answer 6

1. Transmission Electron Microscopes (TEM)
2. Scanning Electron Microscopes (SEM)

Question 7

What type of electron microscope can provide 3D images?

Answer 7

Scanning Electron Microscope (SEM)

Question 8

What are the advantages of using an electron microscope?

Answer 8

Can see more of the sub cellular structures

Question 9

What are the disadvantages of using an electron microscope?

Answer 9

1. Very large and expensive
2. Have to be kept at specific temperature, pressure and humidity controlled room

Question 10

What does resolution mean?

Answer 10

The smallest distance between 2 points that can still be seen as 2 points.
(Higher = clearer)

Question 11

Why must the sample of cells be thin?

Answer 11

So the light source can come through it so that they can be viewed

Question 12

Why do we place a coverslip over the sample?

Answer 12

Prevent contamination
Reduce evaporation
Flatten the sample
Protect objective lens

Question 13

What are the conversions from mm to pm?

Answer 13

———————————>

   X1000.                           X1000.                          X1000.                          X1000

mm (millimetres) —>um (micrometres)—>nm (nanometres) —> pm( picometres)

/1000. /1000. /1000. /1000

                                           <——————————————

Question 14

What are the 4 measurements from highest to lowest?

Answer 14

Milli metres
Micro metres
Nano metres
Pico metres