Question

Identify the correct pair of statements from the following
(i) Binary phloem is commercially important in flax
(ii) Food materials in water conducting tissue are stored in thin-walled cells
(iii) Water movement in vessels is bidirectional
(iv) Mature cells with hydrostatic pressure increases during sugar transport show the presence of peripheral cytoplasm and absence of nucleus

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

Answer 1

Answer: (D)

(ii), (iv).

The xylem is the principal water-conducting tissue of vascular plants. It consists of tracheary elements, tracheids and wood vessels and of additional xylem fibres. It consists of thin walled cells which store food. Sieve tubes are living cells which contain cytoplasm but do not have nucleus. Thus sugar accumulates in large amounts, 2-3 times the surrounding cells. This leads to water movement into sieve cells from xylem elements and causes increased turgor pressure (hydrostatic pressure) inside the sieve cells at the base (remember sieve cells are organized one above the other in long tubular fashion).

So, the correct answer is '(ii), (iv).'