Describe an experiment to demonstrate Osmosis using a named living material. – NABTEB QUESTION

A named living material – egg membrane, urinary bladder, base of pawpaw petiole, yam cup, pawpaw fruit, yam strip, yam tuber.

Description of the experiment:

1. Cut two thick pieces of yam tuber.
2. Peel off the bark
3. Remove the central portion to make them look like cup.
4. label them A and B
5. stand them side by side in a trough or distilled water.
6. pour some quantity of strong salt solution into A
7. leave B without salt solution to serve as a control
8. allow set-ups to stand for 2 – 4 hours.

Result:

1. Water molecules move from the trough into yam cup A,
2. Water level in A rises.
3. Water molecules did not move into yam cup B.

Conclusion:

Living tissues of yam as a semi-permeable membrane allowing water molecules, to move from an area of higher concentration in the trough to an area of lower concentration in the yam cup A. Yam Cup B had no salt solution, water molecule did not move into it, its water concentration was the same as the trough.