Give the characteristics and role of the following:
$(i)$ Cutin
$(ii)$ Suberin
$(iii)$ Sclereids

(N/A) $(i)$ Cutin: Cutin is a waterproof layer of a waxy substance. The epidermis is one cell thick and is covered with a cuticle. This cuticle has a variable thickness and is thicker in xerophytic plants to prevent water loss.
$(ii)$ Suberin: It is a complex polymer present in the walls of cork cells. It makes the cell wall impervious to gases and water,providing protection and preventing desiccation.
$(iii)$ Sclereids: These are sclerenchymatous cells that are short and possess extremely thick,lignified walls with long,tubular simple pits. They are irregular in shape and provide mechanical support and rigidity to plant parts.