Plants Part 4 Roots

Roots Serve 3 important functions: anchors, absorb minerals and water, and they transport those minerals and water Two main types of roots: Taproots are long and thick and have secondary roots emerging from that root. Dicots have taproots. Fibrous roots are many roots of about the same size, each with secondary roots. Monocots have fibrous roots.

Another type of root called the adventitious roots are when the roots emerge from other tissues like the stem and leaves, and prop up the plant in support. Tuberous roots are a lateral root that is specialized to store carbohydrates. Example: yams, cassava

Types of Tissues in Roots Epidermis is one cell layer thick and is the outermost layer of the root. It protects and absorbs water and mineral from the soil. Has specialized cells that form root hairs that increase surface area. The cortex is a layer of cells found just below the epidermis and has some cells that store molecules like starch, transport water and minerals from the epidermal cells to the centre of the root by osmosis. Cortex has a wax coating on the inner layer called the endodermis.

The Casparian strip surrounds the endodermal cells, prevents water from entering back into the cortex. Minerals must be pumped by active transport into the vascular cylinder. This layer controls the movement of water and minerals.

Monocot root vs dicot root The vascular cylinder contains the plant’s conducting tissues: the xylem and the phloem. The xylem conducts water and minerals to the leaves The phloem conducts the sugars from the leaves to other parts of the plant. Monocot root vs dicot root