1.8 Osmosis In Plants

Question 1

Osmosis in plants

Answer 1

-is the external solution is more dilute,water will move into the cell and into the vacuole, causing it to seell, resulting in pressure culled turgor(turgid)
- if the external solution js less dilute,water will move out of thr cell and they will become soft. Eventualky the cell membrane will move away from the cell wall (palsmosys) and it will die. Will cause cytoplasm to detach from cell wall

Question 2

Experiment osmosis method

Answer 2

1. Prepare your potato with a cork boarer, this allows you to take samples of the potato all with the same diameter. Take 3.
2. Cut the ends off as they are impermeable(dosent let water into the plant cells
3. Measure all the cylinders into 3cm lengths and the measure their lengths and record them and then weigh their masses and record them.
4. First place 10mm distilled water into a measuring cylinder and put it into a boiling tube and label it
5. Then measure 0.25 mole of sucrose and put it into boiling tube
6. Also add 0.5 mole of sucrose into a boiling tube.
7. Then put potatoes into all tubes
8. Pour water into a seive and collect the potato
9. Remove all the water from the potato by rolling it on a paper towel.
10. Measure length and mass of potato and record results
11. Do this 2 more times fornthe other 2 solutions and recorded the results
12. Caclulate the difference in mass and length by taking the length after minus the first length and do the same for the mass
13. Take the change in mass and divide that by initial mass and multiply by 100 and that is percentage change.
14. Make a graph explaining the results compared to the inital length and mass.

Question 3

Control,independant and dependant variable for osmosis experiment

Answer 3

Independent variable= the solution in moles
Dependent variable= measure the change in mass of the potato.
Control variable= the same volume of solution, same surface area of potato, the time you kept them in for, same variety of potato
Time= 45 min

Question 4

Recording results

Answer 4

mass change =
final mass - initial mass
• x 100
initial mass
If the potato gains mass, the percentage change will be positive - if it loses mass, the change will be negative.

Question 5

Description of experiment

Answer 5

A)Water moves through the potato by the process of osmosis through a partially-permiable membrane fron a dilute outside solution to a concentrated solution which is the potato which cause the potato to gain mass from 0.0m to 0.18m.
B)The mass of the potato decreased at 0.18m to 0.5m as the potato was more dilute than the outside which was a concentrated and the water moved out the potato by process of osmosis through the partially-permiable membrane.
C)The mass of the potato stayed the same at 0.18 (m) because there was an equalibrium in the movement of water as the same amount of water moved in and out of the potato through the partially-permiable membrane by osmosis.