They are pipe-like, consisting of a group of specialised cells. They transport substances and form a two-way traffic in plants. Which of the following terms qualify for the features mentioned above?
(a) Xylem tissue
(b) Vascular tissue
(c) Root hairs
(d) Phloem tissue
The answer is (d).
The vascular tissue called phloem forms a two-way traffic in plants for transport of substances. It carries the prepared food from leaves to all other parts of plant. This type of movement of food in phloem is called translocation.
Xylem and phloem vessels in plants are called vascular tissues.
The other options, i.e. xylem tissue is not applicable because its movement is unidirectional and is capable of carrying water from the roots upwards to the stem and the leaves. Root hairs absorb water from the soil that moves from cell to cell in the root and ultimately enters the xylem vessels.