Define the term transpiration. Design an experiment to demonstrate this process.

Explanation

Transpiration : Loss of water in vapour form through the surface of leaf / stomata of leaf/ aerial parts of the plant.
Experiment setup:
• Take a potted plant and water it.
• Cover the plant / branch with a transparent plastic sheet.
• Place it in bright sunlight for helf an hour.
• Moisture in the form of droplets is observed inside the plastic sheet.
Detailed Answer:
The loss of water in the form of vapour from the aerial parts of the plant is known as transpiration.
Experiment to demonstrate transpiration :
Requirements : Two small pots, soil, a green plant, a stick of same height as of green plant and plastic sheets.
Method : (i) Take small pots of approximately equal size having equal amount of soil. (ii) One should have a plant and place a stick in another pot. (iii) Cover the soil in both the pots with a plastic sheet so that moisture cannot escape by evaporation. (iv) Cover both the sets with a separate plastic sheet and place in bright sunlight for half an hour.
Observation : Drop of water appear on the inner side of polythene sheet in the pot with a green plant. Whereas no such drops appear in the pot with a stick.
Result: As water drops appear only in the pot with a green plant, it can be concluded that water drops apeared due to transpiration. While the pot with stick does not have any drop as no plant was present.