roots

Most plants have roots, which have many functions: roots take water and minerals out of the surrounding soil; they help to anchor the plant in the soil, and they store extra food. Biennial plants and perennial plants use this food in the spring to grow new leaves and stems.

There are two types of root systems.

A fibrous root system consists of many small roots that begin directly where the stem ends.

A taproot system has one large primary root with secondary roots.

One of the functions of roots is to take in water. Roots take in water by a process called osmosis. Osmosis is the process whereby water flows through a selectively permeable membrane from a place with a higher water concentration to a place where there is less water. Because water is transported away from the root and into the stem, it flows more easily from the soil into the root.

Inside the root, water passes from cell to cell to the centre of the root. In this centre, roots have vessels or tubes which transport the water to the stem and to other parts of the plant.

The larger the surface area a plant has for taking in water, the better it is for the plant. To make this surface area larger, each root has root hairs at its end. Because of this, plants with root hairs are able to take in more water over a shorter period of time.