Question

1. 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 surfaces.
(D) left uncoated.
All the four leaves A, B, C and 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

Answer:

(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.