ICSE Class 10 Answered

(i) Ganong’s potometer                                                                                    

(ii) A potometer does not measure the water loss by transpiration, but it measures the water uptake by the plant. Water absorbed by the plant is not completely lost by transpiration; some of the water is used for cell activities.         

(iii) Transpiration                                                                                                           

(iv) The part marked ‘Reservoir’ is used to bring the air bubble to its original position. This is done by releasing some water from the reservoir into the capillary tube.         

(v) The movement of the air bubble in the graduated tube gives the volume of water lost in a given time, which is equal to the rate of transpiration of the leafy shoot.