Which statement best describes why root hairs are important in nutrient uptake?

• A. They protect roots from pathogens
• B. They transport water to the leaves
• C. They increase the root surface area for nutrient absorption
• D. They store phosphorus

Answer: (C)

Root hairs increase the root’s surface area in contact with soil solution, creating many more sites where nutrients dissolved in water can cross into the root cells. This expanded interface makes nutrient uptake more efficient because absorption happens at the root surface through diffusion and active transport. The more surface area you have, the more minerals the plant can take in from the soil, especially for nutrients that don’t move easily through soil particles.

This isn’t about protection against pathogens, since root hairs aren’t primarily a defensive feature. Water movement to the leaves travels through the plant’s vascular system (the xylem), and root hairs aren’t a direct transport pathway on their own. They also don’t store phosphorus; nutrients are absorbed and distributed through the plant’s tissues as needed. The main point is that increasing the root’s surface area at the soil interface enhances nutrient absorption.