In case of tall trees, where the distance between the soil and the leaves is very large, a proper system of transport is very essential. Explain.

For plants, the soil is the nearest and richest source of raw materials like nitrogen, phosphorus, and other minerals. The absorption of these substances, therefore, occurs through the part in contact with the soil, namely roots. If the distances between soil-contacting organs and chlorophyll-containing organs are small, energy and raw materials can easily diffuse to all parts of the plant body.

But in the case of tall trees and shrubs these distances become large because of changes in plant body design therefore, diffusion processes will not be sufficient to provide raw material in leaves and energy in roots. Hence, the need for a proper system of transportation arises in plants.