Question

The transportation in xylem in usually unidirectional, whereas in phloem it is __.

Answer 1

The transportation of water in the xylem takes place only from the roots to the leaves. Therefore, the movement of water and nutrients in the xylem is unidirectional. However, the movement of food in the phloem is bidirectional (both upward and downward). The organic solutes may be transported from the leaves where they are synthesized to the roots, where they are stored. They may also be moved from the storage organs like roots, stem, etc. to the apical or lateral meristems during growth.