Electron microscopes

Question 1

What are the 2 types of electron microscopes?

Answer 1

Transmission electron microscope and scanning electron microscope

Question 2

What is a transmission electron microscope?

Answer 2

Electrons are transmitted through specimen, can see cell internally

Question 3

What is a scanning electron microscope?

Answer 3

electrons hit the surface of specimen then bounce off surface, gives 3D image of the surface of cell

Question 4

What are the types of preparation?

Answer 4

fixing, staining with heavy metals, dehydration, and embedding in resin

Question 5

Why do we use preparation?

Answer 5

so theres a hard surface for electrons to bounce off and hit

Question 6

Why are dead specimens used?

Answer 6

since its carried out inside a vacuum, only dead specimens used due to harsher prep needed. can cause artefacts to appear

Question 7

What are artefacts?

Answer 7

Things created on the slide when prepping (e.g. bubbles)

Question 8

Why do we dehydrate specimens?

Answer 8

To dry out the specimen to go into the vacuum

Question 9

Why are electron microscopes better than light microscopes?

Answer 9

A beam of electrons is used rather than light, they have a shorter wavelength = better resolution, cell organelles visible

Question 10

Why is having higher resolution + magnification important?

Answer 10

Means you can see cells clearer + in more detail

Question 11

How are electrons microscopes different to light microscopes?

Answer 11

Theyre more expensive, have higher resolution + magnification, and produce black + white images