Question

Question 4
Which cell does not have perforated cell wall?

(a) Tracheids
(b) Companion cells
(c) Sieve tubes
(d) Vessels

Answer 1

(a) Tracheids

Companion cells, vessels and sieve tubes are tubular cells with perforated walls.

Tracheids and vessels are xylem elements and are concerned with the transport of water.

Sieve tubes are slender tube-like structures with their end walls perforated by numerous pores and are called sieve plates. They are phloem elements and are main food conducting elements.

Companion cells possess numerous mitochondria and ribosomes and are supporting units of sieve tubes.