Question

Select the correct statement(s) pertaining to transpiration process in plants:
I. It is a necessary evil for plants.
II. Loss of water takes place through hydathodes in vapour form.
Ill. It may also occur through lenticels.
IV. The process is active during night in C${}_3$ plants.

• A. I and IV are correct
• B. II and IV are correct
• C. I and Ill are correct
• D. Ill and IV are correct

Answer 1

The correct option is C I and Ill are correct

Transpiration is the loss of water in the form of vapours from the plant parts through stomata (mainly) and lenticels (in some amount). Transpiration is a necessary evil for plants because

• creates transpiration pull for absorption and transport of plants
• supplies water for photosynthesis
• transports minerals from the soil to all parts of the plant
• cools leaf surfaces, sometimes 10 to 15 degrees, by evaporative cooling
• maintains the shape and structure of the plants by keeping cells turgid.

Rate of transpiration is very low during the night in most plants.

Guttation (loss of water in the form of water droplets) takes place through hydathodes.