Microscopes

Question 1

How to prepare a microscope slide

Answer 1

Cut a thin layer- so light can pass through
Place on slide and add drop of water- to prevent cell from drying out
Add iodine- to stain starch and distinguish organelles
Place cover slip on top- at an angle to prevent air bubbles
Bring stage closer
Use objective and fine lens to bring cell into focus

Question 2

Micrometers to metres

Answer 2

x1000 and x1000 again

Question 3

Millimetres to micrometers

Answer 3

x1000

Question 4

Cm to mm

Answer 4

x10

Question 5

How do light microscopes work

Answer 5

Light passes through the specimen and is bent through the lens

Question 6

How do scanning electron microscopes work

Answer 6

A beam of electrons move back and forth across the surface of the cell or tissue and are scattered in different directions producing a detailed image of a 3d surface

Question 7

How do transmitting electron microscope work

Answer 7

Sample is cut into extremely thin slices, using a diamond cutting edge, and the electron beam passes through the cellls rather than skimming over surface

Question 8

+ and - of light microscopes

Answer 8

+ cheaper
+ easier
+ can see live specimen
- low magnification and resolution

Question 9

+ and - of TEM

Answer 9

+ complex fixation, high mag and res
+ can see inside cell organelles
- cells are unalive as places in vacuum
- 2d image produced as electrons pass through

Question 10

+ and - for SEM

Answer 10

• can see outside of cells
  + 3d image produced as electrons reflect off