Question

The diagram below represents an experiment to demonstrate a certain phenomenon in a green plant:

1. Will the level of mercury in the glass tubing rise off all?
   Which conducting tissue of the plant does the glass-tubing represent?
2. Define transpiration.
3. How will the rate of the above process differ if the environment of the plant has:
   1. less humidity?
   2. high temperature?
4. State any two advantages of transpiration to the plant.
5. Draw a neat, labelled diagram of a plasmolysed cell.

Answer 1

1. The level of mercury in the glass tubing will rise. The glass-tubing represents xylem.
2. Transpiration is the loss of water in the form of vapour from the aerial parts of the plant.
3. 1. Less humidity increases the rate of transpiration.
   2. High temperature increases the rate of transpiration.
4. Two advantages of transpiration to the plants are:
   1. Cooling effect.
   2. Creation of suction force for ascent of sap.
5.