transpiration is a necessary evil ? give reason

Transpiration is considered to be a necessary or unavoidable 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