Transportation of Food and Minerals in Animals and Plants — BIOLOGY STD 8 — Question

Most of the minerals needed by plants are dissolved in water in the soil. Molecules of minerals are often more crowded inside the root hair than they are in the soil. Root hairs can still absorb minerals from the soil. The movement of molecules from an area where they are present in less concentration to an area where they are present in more concentration is called active transport which requires energy Minerals are then transported through the xylem to all parts of the plant.

However, active transport is not the only way by which plants take minerals from the soil. Plants can absorb minerals by diffusion also when concentration of mineral molecules is higher in the soil than inside the root. The water and minerals absorbed by roots are conducted upwards to the leaves, flowers and other parts of plant. The upward movement of sap that contains water and minerals is called ascent of sap.