Transport in Plants Question 48
48. Which of the following is used to determine the rate of transpiration in plants?
[1992]
(a) Porometer/hygrometer
(b) Potometers
(c) Auxanometer
(d) Tensiometer / Barometer
Show Answer
Answer : b
Hints & Solutions
(b) Potometer is an apparatus used for measuring the rate of transpiration. The potometer does not measure the rate of transpiration accurately because not all of the water that is taken by the plant is used for transpiration (water taken might be used for photosynthesis or by the cells to maintain turgidity). The potometer measures the rate of uptake of water. To measure transpiration rate directly, rather than the rate of water uptake, utilize a scientific instrument which quantifies water transfer at the leaves.
