Question

Short / Long answer type questions.
Transpiration is a necessary evil. Justify the statement. Discuss the significance of transpiration.

Answer 1

Transpiration is a necessary evil. An actively photosynthesizing plant requires a good quantity of water and minerals. Transpiration creates a pull for absorption and translocation of water as well as minerals. But photosynthesis rate is limited by the available amount of water which slowly gets transpired. Transpiration and photosynthesis occur simultaneously due to the opening of stomata which leads to gaseous exchange but water vapour also escapes side by side. Only one percent of the total water absorbed is utilized in photosynthesis and plant growth.

Significance includes:

1. Creates transpiration pull for absorption and transport in plants.

2. Supplies water needed for photosynthesis.

3. Transports minerals along with water from the soil to various parts of the plant.

4. Causes cooling effect on leaf surfaces. Can lower temperature up to 10-15 degrees.