Carry out the following osmosis experiment:

Take four peeled potato halves and scoos each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water.

(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.

Keep these for two hours. Then observe the four potato cups and answer the following:

(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D

Sciences - Exemplar Problems

Chapter 5. The Fundamental Unit of Life



(i)Water gathers in B and C because of exosmosis in the cells of the peeled potato as the sugar with water is more concentrate.
(ii)To demonstrate that no osmosis takes place in the absence of a more concentrate solution as A is empty
(iii)As the process of osmosis is not carried out in these cups.