Life Processes — Science STD 10 — Question

Plants need vascular bundles for transport the food, minerals and water. When water and minerals are absorbed by the roots, then this cannot be direct reach to the upper parts of plants. So xylem tissue takes them and transport it to the upper part of plant like shoot, stem and mainly for leaves for preparing food by photosynthesis. If roots do work of absorption of water and minerals then it also needs energy. For example if we do any work then we need energy to do that work. It is same with the roots. They need their food for energy. When leaves do photosynthesis and form food, then this cannot directly get by the roots. So phloem is used for transporting the food from leaves to roots. Hence plants need transporting system. But bryophtes do not need this system because they are thallophytes.