Effect of Osmosis on Plant Tissue

Question 1

What is Osmosis

Answer 1

Movement of water molecules from an area of high concentration to an area of low concentration through a partially permeable membrane.

Question 2

What happens when plant cells are place in water?

Answer 2

Water causes plant cell to expand as osmosis occurs.

Question 3

This is a big one. You’ll need to cover 8 points

What is the practical for testing effects of osmosis on plant tissue?

Use terms including: Peel, Cork Borer, Trim, Scalpel, Measure, Test Tube, Paper Towels

Answer 3

1. Peel potato (skin affects Osmosis)
2. Prepare 3 potato samples using cork borer to make them same diameter.
3. Trim cylinders/ samples to same length using scalpel.
4. Measure length (ruler) and mass (balance) of each cylinder/sample
5. Place each sample into testube (3 test tubes in total)
   Add 10cm^3 of 0.5 molar sugar solution, 0.25 and distilled water to each test tube respectively.
6. Leave for period of time (e.g. overnight) to allow for osmosis to occur.
7. Remove samples and blot dry using paper towels to remove surface moisture.
   8. Measure length and mass again

Question 4

What is the equation for percentage change?

Answer 4

% change = Change in value / Original value
* 100

Question 5

What information do we obtain from this experiment?

Answer 5

In water, sample gains mass due to osmosis.
In concentrated sugar solution, sample loses mass as water moves out by osmosis.