The diagram below represents an experiment to demonstrate a certain phenomenon in a green plant (a leafy shoot fixed by rubber tubing to a glass tube standing in mercury): The diagram below represents an experiment to demonstrate a certain phenomenon in a green plant (a leafy shoot fixed by rubber tubing to a glass tube standing in mercury):
State any two advantages of transpiration to the plant.
Topic: Advantages of transpiration
Answer
- It creates the TRANSPIRATION PULL — the suction that draws water and dissolved minerals up from the roots to the leaves against gravity (the ascent of sap).
- It COOLS THE PLANT, since the evaporation of water from the leaf surface absorbs latent heat and prevents overheating in strong sunlight.
Two advantages, and these two are the strongest.
THE TRANSPIRATION PULL is the more important: without it water could not be lifted to the top of a tall tree. A third, if three are wanted: it maintains the flow of MINERAL SALTS, which travel dissolved in that water.
THE WIDER POINT worth a closing line: transpiration is sometimes called a NECESSARY EVIL, because the plant loses enormous quantities of water by it. But the loss is unavoidable — the stomata must open to admit carbon dioxide for photosynthesis, and water inevitably escapes through the same pores.