Choose the correct answer from each of the four options given below:
Transpiration is useful to the plant because it:
Topic: Usefulness of transpiration
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Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) Creates a suction force for absorption of water from the soil.
The evaporation of water from the leaves creates the TRANSPIRATION PULL — a suction transmitted down the unbroken column of water in the xylem, which draws water up from the roots against gravity.
This is the chief force behind the ASCENT OF SAP, and it is what allows water to reach the top of a very tall tree.
Options (b), (c) and (d) all describe PHOTOSYNTHESIS, not transpiration — photophosphorylation, glucose synthesis and the splitting of water are all events of the light or dark reaction. Three wrong options drawn from a neighbouring chapter is a common design, and recognising it narrows the choice instantly.
A second genuine benefit, if a question asks for two: transpiration COOLS the plant, since evaporation absorbs latent heat from the leaf surface.
Creates a suction force for absorption of water from the soil.