Water Potential of Potato Tuber Cells: The Density Method

... Valentina Zunarelli IB Biology Practical Water Potential of Potato Tuber Cells: The Density Method Introduction Aim To find out the water potential of potato tuber cells by testing whether a drop of coloured solution sinks or floats in test tubes containing solutions of different densities. This is called the density method. Hypothesis My hypothesis is that the drop of coloured solution will rise if the tissue gained water from the solution, making it denser. However, if the water potential is the same as the solution's, the drop will neither fall nor rise. Method Firstly label seven test tubes: 0.10, 0.15, 0.20, 0.25, 0.30, 0.50, 1.00 mol dm-3. Then, using a separate graduated syringe in each case, place 5cm3 of the appropriate solution in each test tube. Pipette 3cm3 of sucrose solution with each sucrose concentration into other test tubes and label them. Place one drop of methylene blue in each of these test tubes. This will colour the

want to read more? →