Given below is an apparatus which was set up to investigate a physiological process in plants. The setup (a potted plant under a bell jar, the pot sealed in a rubber sheet, standing on a glass plate with vaseline) was placed in bright sunlight. Answer the questions that follow: Given below is an apparatus which was set up to investigate a physiological process in plants. The setup (a potted plant under a bell jar, the pot sealed in a rubber sheet, standing on a glass plate with vaseline) was placed in bright sunlight. Answer the questions that follow:
Name the process being studied. Define the process.
Topic: Transpiration
Answer
The process is TRANSPIRATION.
TRANSPIRATION is the loss of water in the form of WATER VAPOUR from the AERIAL parts of a plant — mainly through the stomata of the leaves, and to a smaller extent through the cuticle and the lenticels.
The WATER DROPS condensing on the inside of the bell jar are the evidence: water vapour has escaped from the plant and condensed on the cooler glass.
Two elements must appear in the definition: the water is lost as VAPOUR, and from the AERIAL parts.
VAPOUR distinguishes transpiration from GUTTATION, which gives liquid DROPS through hydathodes. AERIAL rules out the roots, which ABSORB water rather than losing it — which is why "all parts of the plant" is a wrong definition.