transpiration is a necessary evil. justify the statement.
Transpiration is considered to be a necessary evil because it leads to loss of water from plants but provides the plant with several advantages as well.
- Creates transpirational pull for transport
- Supplies water for photosynthesis
- Transports minerals from soil to all parts of a plant
- Cools the surface of the leaves (due to the evaporation of water)
- Keeps the cells turgid; hence, maintains their shape
The loss of water in the form of vapors from aerial parts of the plant is called transpiration. Transpiration is said to be a necessary evil because it is an inevitable, but potentially harmful, consequence of the existence of wet cell surfaces form which evaporation occurs. Loss of water from the plant results wilting, serious desiccation and often death of a plant if a condition of drought is experienced.
It is supposed to help the plant in the following ways.
- Excess water getting into the plant might decay the cells. Transpiration prevents it by removing the extra water.
- Transpiration stream helps in the distribution of nutrients to all the parts of the plant body.
- Fresh and cool water reaches all the parts of the plant body and this reduces the metabolic heat acting as a coolant.
- Transpiration indirectly helps in the uptake of salts as the latter get into the plant together with water.
- Upward movement of water (Ascent of sap) is due to the suction force created by transpiration.
That is why transpiration is often called a necessary evil.
Creates transpirational pull for transport
Supplies water for photosynthesis
Transports minerals from soil to all parts of a plant
Cools the surface of the leaves (due to the evaporation of water)
Keeps the cells turgid; hence, maintains their shape
*Transpiration results in transpiration pull which thereby increase the rate of absorption of water along with minerals from the soil through roots.
*Transpiration helps in transportation of absorbed minerals to all the parts of the plant.
*Transpiration provides water for the process of photosynthesis.
*Transpiration helps in cooling the structures of the plant when exposed to hot sunlight.
*Transpiration helps the cells to maintain their turgidity.