Question

The given figure represents an experiment:

1. Leaf A was coated with grease on both surfaces.
2. Leaf B was coated with grease on the lower surface.
3. Leaf C was coated with grease on the upper surface.
4. Leaf D was left without any application of grease. All four leaves A, B, C and D were left in a room for about 24 hours.
   1. Which leaf dries first? Give reason.
   2. Which leaf dries last? Give reason.

Answer 1

1. Leaf D: the leaf with no greasing on either surface would dry first, as it would shed the maximum amount of water from both surfaces.
2. Leaf A: The leaf that was greased on both surfaces would dry out due to the fact that grease prevents water evaporation and transpiration by means of stomata, which are more prevalent on the lower surface of the leaf.