Answer
The vascular tissue system allows the leaves to send the products of photosynthesis to the roots where they are needed but cannot be produced and, at the same time, for the roots to send water and minerals from the soil to the shoot, where it is needed but cannot be absorbed.
Work Step by Step
Think of the vascular tissue system as a highway on which trucks can travel in either direction. A city which makes bread can send its products over the highway to another city which grows vegetables, and vice versa. The two cities are the two ends of the plant, connected by vascular tissue.