Question

Answer the following in detail.

Explain the process of transpiration. Describe some factors that affect it. 

Answer 1

Large quantities of water are absorbed by plants for photosynthesis and other processes. Excess of water is lost in the form of water vapour through the stomata and lenticels from the aerial parts of the plant by transpiration. It helps plants to maintain the concentration of sap inside the plant body. If plants do not remove excess water through transpiration, the dilute sap will prevent further absorption of water and minerals from the soil.

Factors affecting the rate of transpiration are :

1. Sunlight: Rate of transpiration is more during the day as stomata are open. Stomata remain closed at night and thus no transpiration takes at night.
2.  Temperature: Transpiration is more on hot days than on cold days.
3.  Wind: Blowing wind removes water vapour faster from the leaves and hence transpiration rate increases.
4.  Humidity: If the air is humid, the rate of transpiration is low.
   In the rainy season, transpiration is less since humidity is more.