Question

Why transpiration is called necessary evil?

Answer 1

Transpiration:

1. It is the loss of water through the aerial parts of the plant.
2. The water is typically lost in the form of water vapours.
3. The tiny opening present on leaves i.e stomata helps in the movement of water out of the plant.

Transpiration is called necessary evil because:

1. It causes around 90% of water loss for the plant.
2. But it is necessary for the plant since it causes a suction force known as transpirational pull.
3. This suction force helps in transporting water up to larger heights in plants against the force of gravity.
4. It also leads to excessive loss of water sometimes causing the wilting of leaves.
5. Thus, transpiration is termed a necessary evil.