A potometer with a leafy shoot weighed 18.9g initially and weighed 17.9g after one hour. From this it follow that
the shoot absorbed 1g of water per hour
1g of water per hour evaporates from the potometer
the shoot lost 1g of water per hour
the potometer water receded at the rate of 1g per hour
the shoot was respiring and lost weight at rate of 1g per hour
Correct answer is C
The amount of water lost is (18.9 - 17.9)g = 1g. Hence, the water lost by the shoot is 1g.