Transpiration is a nessecary evil.Comment.

Asked by Annette | 24th Jun, 2009, 04:43: PM

Expert Answer:

Transpiration is said to be a necessary evil because it is an inevitable, but potentially harmful, consequence of having moist mesophyll membranes exposed to the atmosphere. Since water is one of the most important compounds needed for various important life processes, a loss of water by transpiration is obviously harmful. Loss of water from the plant results in wilting, serious desiccation and often death of a plant if a condition of drought is experienced. Besides wilting, other harmful effects of excessive transpiration include inhibition of protein synthesis and breakdown of proteins and retardation of metabolic processes like photosynthesis. Even mild water stress results in reduced growth rate. Despite its apparent inevitability, transpiration is also of great significance for the plant.  Water is conducted in most plants due to transpiration pull. Minerals dissolved in water are distributed throughout plant body by transpiration. Evaporation of water from the exposed surface of cells of leaves has cooling effect on plant.  Wet surface of leaf cells allow gaseous exchange.

Answered by  | 25th Jun, 2009, 08:33: PM

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