Question

In an experiment, four freshly plucked leaves (A-D) of a plant, such as those of china – rose, were treated as follows:
(a) Coated with Vaseline on its upper surface.
(b) coated on the lower surface.
(c) coated on both surface
(d) left uncoated.
All the four leaves A, B, C & D were left in a room for about 24 hours.
(i) which leaf would become most limp? Why?
(ii) which leaf would show least limping? Why?

Answer 1

(i) The leaf D would become most limp. This is because water would be lost through transpiration from upper as well as the lower surface of leaf D since it is uncoated.

(ii) The least limping would be shown by leaf C since its upper and lower surfaces have been coated with vaseline. So no water is lost from the leaf through transpiration since the stomatal openings get blocked by vaseline.