Why do you think that a thick cuticle on the outer wall of epidermis is advantageous for a plant living in the desert but disadvantageous for a plant living underwater? [Pg. No. 34]
A thick cuticle reduces the loss of water through evaporation. This is beneficial for desert plants because water is scarce in their surroundings. However, in underwater plants, a thick cuticle is unnecessary and disadvantageous because water is readily available and gases can diffuse directly through the plant surface. A thick cuticle may hinder this exchange of gases and materials.