Question

Potometer is an instrument that measures
A. Respiration
B. Transpiration
C. Growth
D. Photosynthesis

Answer 1

A device which is used to measure the uptake of water in a process where there is movement of water within the plants. Potometer is a device which is used to measure the uptake of water.

Complete answer:
So, if we look at the options, option A is Respiration. In the process of respiration there is movement of oxygen from the outside environment to the cells within the tissues and transport the carbon dioxide in the opposite direction. So there is no uptake of water but a potometer is used to measure the uptake of water. Therefore, this option is incorrect and it gets eliminated.
Moving to next option B which is Transpiration. It is a process of movement of water within the plants and there is loss of water too through the stomata in the form of water vapours. That uptake of water is measured by the potometer. Therefore, this option is the correct one.
Moving to option C which is Growth. It is a process of growing, developing, increase in size or you can say growth is a stage of development. There is no such uptake of water in this process which requires measurement. Therefore it is the incorrect option and it gets eliminated.
Last option D is photosynthesis and it is the process by which green plants make their food by the use of sunlight to form the nutrients from carbon dioxide and water. There is involvement of chlorophyll and it generates oxygen as the by product. This cannot be the correct option since a potometer is used to measure the uptake of water in transpiration.

Thus, the correct answer is option B which is transpiration.

Note: Transpiration is a process of movement of water within the pant and there is loss of water too through the stomata in the form of water vapours. That uptake of water is measured by the potometer which makes option B the correct one.