Question

1. A plastic container fill of water was stoppered using a piece of stem obtained from a young maize plant whose bark had been peeled off. The next day it was noted that the stopper closed the container very tightly. Explain. 
2. State the observation made when a similar experiment was set up but using boiled piece of maize stem obtained from a young maize plant whose bark had been peeled off. 
3. Explain the observation stated in (2) above.

Answer 1

1. Vacuole of the cortical/inner cells of the stem was hypertonic to the water; the inners/cortical cells absorbed water by osmosis; and became turgid increasing in size closing the container very tightly;
2. stem stopper remains the same/ does not close the container very tightly;
3. Boiling destroys the cell membrane of the stem cells preventing osmosis from occurring;