Question

Which of the following statements is true?
(a) Vessels are multicellular with narrow lumen
(b) Tracheids are multicellular with narrow lumen
(c) Vessels are unicellular with wide lumen
(d) Tracheids are unicellular with wide lumen

Answer 1

Answer is option "d"

Explanation:

• Vessels are formed by a series of cells placed longitudinally with their separating walls dissolved. The wall of the vessels are thick due to deposition of lignin. The protoplast is absent at maturity, therefore dead with large lumen.
• Tracheids are unicellular whereas vessels are multicellular. Tracheids are more lignified, so have narrow lumen whereas vessels have less lignified, so have wide lumen.
• Hence, the right answer is option d " trachelds are unicellular with wide lumen".