Question

9. 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. Now,
(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​

Answer 1

Answer:

(i) Water accumulates in the hollowed portions of B and C as a difference in the water concentration

is observed. Thereby, endosmosis occurs as the cells act as a semipermeable membrane.

(ii) Potato A is essential in this experiment as it is significant to compare different scenarios seen in

potato cups B, C and D. The potato A in this experiment clearly shows that the potato cavity on its

own cannot bring about water movement.

(iii) Cup in A does not show any change in the water flow concentration for osmosis to occur, which

requires the concentration to be higher than the other. Cells in cup D are dead, thus there is no

existence of a semipermeable membrane for water flow. Consequently, osmosis does not occur.