Draw a neat diagram of structure of root hair showing vacuole, mitochondria and nucleus.

Answer: [Diagram to be drawn: a single epidermal cell of the root (epiblema) with a long, tubular, unbranched outgrowth (root hair) extending into the soil between soil particles. Label: cell wall (outer pectin layer, inner cellulose layer), plasma membrane, thin lining of cytoplasm, a large central vacuole filled with cell sap occupying most of the cell and the hair, the nucleus lying in the cytoplasm near the tip of the root hair, and several mitochondria scattered in the peripheral cytoplasm.]

Points to remember: the root hair is a unicellular extension of an epidermal cell, about 1 to 10 mm long; it has a thin, permeable wall and a large vacuole with cell sap of higher concentration than soil water, which helps absorption of water by osmosis; the mitochondria supply ATP for active absorption of minerals.