Microscopes

Question 1

What is magnification?

Answer 1

The factor by which an image has been enlarged.

Question 2

What is resolution?

Answer 2

The ability to see closely placed objects as separate structures.

Question 3

What are the key features of a light microscope?

Answer 3

• 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.

Question 4

What are the key features of TEM’s?

Answer 4

• 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.

Question 5

What are the key features of SEM’s?

Answer 5

• 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