Preparing and examining plant cells using a light microscope

Question 1

List the 7 steps to prepare the slide

Answer 1

1. Remove the outer layer, dry scaly leaves of an onion.
2. Use forceps to get a stip of thin, transparent epidermis.
3. Place on a microscope slide.
4. Add a few drops of iodine solution. (stains the nucleus orange and the cytoplasm yellow)
5. Add a coverslip (prevents the cell from drying out and prevents the lens from getting stained).
6. Blot off any surplus iodine if necessary.
7. At step 4, water can be used instead of iodine.

Question 2

Why is iodine used to stain the cell?

Answer 2

stains the nucleus orange and the cytoplasm yellow so that it can be viewed clearly.

Question 3

Why does the cover slip need to be lowered slowly at a 45 degree angle?

Answer 3

To prevent air bubbles.

Question 4

Why must the sample of a plant cell be thin?

Answer 4

So that the light from the microscope can travel through it.