Phloem tissue forms a pipe like a network of specialized cells that transport the food from leaves to all other parts of the plant. It is a two-way traffic i.e from leaves to parts of plants present upward and downward which are roots.

Xylem, which with phloem forms the vascular tissue, transports the water absorbed by roots to the leaves. It forms a one-way path in plants. Root hairs increase the surface area of absorption of water by the roots.