3.Types of electron microscope

Question 1

Name the 2 types of electron microscopes?

Answer 1

Transmission electron microscope TEMs

Scanning electron microscope SEMs

Question 2

What are TEMS?

Answer 2

Use electromagnets to focus a beam of electrons which is then transmitted through the specimen.

Denser parts of specimen absorb more electrons, which makes them look darker on the image

Question 3

Advantages of TEMs

Answer 3

High resolution images

Able to see internal structure of organelles like granum in chloroplasts.

Question 4

Disadvantages of TEMs

Answer 4

Have to view specimen through vacuum so cannot view living organisms.

Only used on thin specimens.

Question 5

What are SEMs?

Answer 5

Scan a beam of electrons across the specimen.

This knocks off electrons from specimen which then gather in cathode ray tube to form image.

Question 6

Advantages of SEMs

Answer 6

Images you end up with show surface.
3D.
Used on thick specimens.

Question 7

Disadvantages of SEMs

Answer 7

Low resolution images.

Only used on non-living specimens.