Explain6 marksChallenge
A student investigates water transport in a herbaceous dicotyledonous plant, such as sunflower. Transverse sections of the stem, root, and leaf are examined using a photomicrograph. In the stem, xylem vessels are arranged in a ring near the centre; in the root, the xylem forms a star-shaped core with phloem between the arms; in the leaf, vascular bundles in the midrib have xylem on the upper side and phloem on the lower side.
Explain how the structure of xylem vessel elements in the stem of this plant is adapted for the efficient transport of water from the roots to the leaves.