1
Q
Equipment (8p)
A
Forceps
Onion
Microscope slide
Iodine
Mounted needle
Cover slip
Microscope
Scalpel
2
Q
Method (5p)
A
1) Cut a small piece of onion
2) Peel thin membrane away from inner side of layer using forceps
3) Lay the skin flat on slide and add a few drops of iodine
4) Lower cover slip onto slide using mounted needle- make sure there are no trapped air bubbles
5) Put the slide on the microscope stage and focus the microscope until there is a clear image
3
Q
Risks (2p)
A
- Scalpel is sharp
- Iodine is corrosive
4
Q
Purpose of iodine
A
To make the onion visible under the microscope
