# QN: HOW DO YOU CALCULATE THE WATER POTENTIAL OF CELLS IN A POTATO?

SORAIYA MANJI

I.B. 1 BIOLOGY

QN: HOW DO YOU CALCULATE THE WATER POTENTIAL OF CELLS IN A POTATO?

Aim

My aim was to estimate the water potential of potato tuber cells using sucrose solutions of different solutions.

Hypothesis

I assumed that the mass of the potato cylinder in distilled water will remain the same after leaving it in the water for about two hours because of no difference in the concentration. I also assumed that as the concentrations of the solutions increase, the mass of the potato cylinder after leaving it in the solution for two hours will decrease, and the change in mass will be higher with greater concentration. This is because more water will come out of a cell with less concentration of solution inside than outside.

Variables

The independent variable is the concentration of all the sucrose solutions, i.e. 0.2, 0.4, 0.6, 0.8 and 1.0 mol/dm3. The dependent variable is the mass of the potato cylinders before and after leaving them in the sucrose solutions. The controlled variables were the amount of solution in each test tube.

Apparatus and reagents

• Test tubes
• Stoppers
• Cork borer ( of 10mm diameter)
• Metal knife
• Filter papers
• Forceps
• Digital balance( to weigh intervals of 0.01g)
• Distilled water
• Sucrose solutions ( 0.2, 0.4, 0.6, 0.8, 1.0 mol/dm3)
• Potato tuber

Method

1. First of all, six test tubes were labelled with D.W, 0.2, 0.4, 0.6, 0.8 and 1.0 mol/dm3.
2. One test tube was filled with water, and the rest with sucrose solutions with their respective concentrations.
3. After that, six potato cylinders about 5 cm in length ...