Give reasons for the following:
$(i)$ Bark of a tree is impervious to gases and water.
$(ii)$ In desert plants,epidermis has a thick waxy coating.
$(iii)$ Epidermal cells of the roots generally have hair-like parts.

(N/A) $(i)$ Cells of the bark are dead and compactly arranged without intercellular spaces. They contain a chemical substance called suberin in their cell walls,which makes them impervious to gases and water.
$(ii)$ The thick waxy coating on the epidermis is composed of cutin,a chemical substance with waterproof properties. This coating helps in protecting the plant against water loss and parasitic fungi.
$(iii)$ The primary function of epidermal cells in roots is water absorption. The hair-like extensions,known as root hairs,significantly increase the total surface area available for absorption.