3.3. Root

Roots, which typically make up the underground portion of the plant, are complex and important organs. The structure and growth of the root differ from the aboveground shoot (stems and leaves), as do functions between the two systems. The specialized root and shoot systems of a plant complement each other through a division of labor. Aboveground, the green tissues of the shoot photosynthesize, creating sugars that may be used to fuel growth throughout the plant, including the roots. Belowground, the root offers the shoot anchorage and storage. In addition, it provides the shoot water and minerals from the soil, which are essential for growth. In addition to water absorption, the roots are also the sole source for nutrient uptake.  Roots also acquire many inorganic micronutrients such as potassium, calcium, chloride, iron, and phosphate from the ground; that are essential in several cellular processes. The highly branched nature of roots, coupled with extensions of epidermal cells called root hairs, provides the plant with a tremendous amount of subterranean surface area for maximum water and nutrient uptake.