Question

What is transpiration?Explain various factors affecting it.

Answer 1

Plants often require an excretory system, like all living organisms, to discharge excess water from their bodies. This process of extracting excess water from the body of the plant is referred to as transpiration. In general, it is the evaporation of water from the leaves' surface.

Complete answer:
Transpiration is the biological mechanism by which water from the aerial portions of plants is lost in the form of water vapour. Water molecules in the plant tissues are separated from the aerial parts of the plants during the process of transpiration. In growth and development, only a limited amount of water consumed by the plants is utilised. In the process of transpiration, the rest is eliminated.
There are three different types of transpiration in plants:
i) Stomatal transpiration
ii) Lenticular transpiration
iii) Cuticular transpiration

Different variables influencing the transpiration rate are:
Cellular Factors
-The cellular variables controlling the transpiration rate are:
-The Leaf Orientation,
-The plant's water status,
-Leaf Structural Peculiarities,
-Total number of stomata in a leaf and their distribution.

Environmental factors
The environmental variables controlling the transpiration rate are:
-Light,
-Moisture,
-Temperature
-Pressure from the environment,
-Speed or velocity of wind.

Relative Humidity
The amount of water vapour present at a given time and temperature in the air is expressed as a percentage of the amount required at the same temperature for saturation. The transpiration rate is inversely proportional to that of relative humidity. The lower the relative humidity is the rate of transpiration.

Temperature
Also in darkness, a high temperature decreases the relative humidity and opens the stomata. The rate of transpiration rises as a result.

Light
During the day the stomata open and close up in the dark. The presence of light is directly proportional with the rate of transpiration.

Air
The transpiration rate is low if the air is still. This is due to the concentration of water vapor across the transpiring organs and the air diffusion pressure deficit being decreased.
The saturated air around the leaves is lost if the air is moving, and the transpiration rate rises.

Availability of Water
The rate of transpiration is directly proportional to water absorption from the soil by the roots. The closing of stomata and wilting is caused by a decrease in water absorption, thus reducing the transpiration rate.

The Leaves' Surface Area
A leaf with more surface area would display a greater rate of transpiration than a leaf with a lower surface area.

Note: A critical mechanism is transpiration in plants. Excess water will build up in the plant cells in the absence of transpiration, and the cells will finally burst. More than 10 percent of the moisture on earth comes from transpiration. It is understood that it is a part of the cycle of water.