Osmosis in Yam

Activity: Demonstrating osmosis in a living tissue (yam)

Material: Tuber of yam, water trough, knife, concentrated salt solution, boiled yam.

Method:

1. Cut and peel off the yam.
2. Cut the yam into two and make a cavity in them including the boiled yam. Label the yams A, B, and C
3. Stand the pieces of yam in a water trough contain water and mark the water level on the water trough.
4. Pour water in the cavity of yam A, salt solution in the cavity yam B and salt solution in the cavity of boiled yam C.
5. Leave the set-up for 8 hours.

The water in the water trough in set-up B will reduce in level because the water will move into the cavity.

In setup B, the salt solution in the yam cavity will increase, the water level in the water trough will decrease. This is due to the movement of water from the water trough through the yam (semi-permeable membrane) into the salt solution in the yam cavity

Observation: the level of salt solution in the cavity of yam

A will remain the same. The salt solution in cavity of yam B will rise. The salt solution in cavity of yam C will remain the same.