Question

Which of the following statements is/are not correct?
(i) Water and minerals, and food are generally moved by a mass or bulk flow system.
(ii) Bulk flow can be achieved either through a positive hydrostatic pressure gradient or a negative hydrostatic pressure gradient.
(iii) The bulk movement of substances through the conducting tissues of plants is called translocation.
(iv) Xylem translocates organic and inorganic solutes, mainly from roots to the aerial parts of the plants.
(v) Phloem translocates water, mineral salts, some organic nitrogen and hormones, from the leaves to other parts of the plants.

• A. (ii), (iii) and (v)
• B. (ii), (iii) and (iv)
• C. (iv) and (v)
• D. (ii) and (v)

Answer 1

The correct option is C (iv) and (v)

Statements (iv) and (v) are not correct because of the following reasons:

Xylem is associated with the translocation of mainly water, mineral salts, some inorganic nitrogen and hormones from roots to the aerial parts of the plants.

Phloem translocates a variety of organic and inorganic solutes mainly from the leaves to other parts of the plant.

Translocation is the bulk movement of substances through the conducting tissues (vascular system) over longer distances.

Water, minerals and food are generally moved by a mass or bulk flow system. Mass flow is the movement of substances in bulk from one point to another as a result of pressure differences between the two points. This is unlike diffusion where different substances move independently depending on their concentration gradients. Bulk flow can be achieved either through a positive hydrostatic pressure gradient or a negative hydrostatic pressure gradient.