5. The living component of phloem tissue is
(a) Sieve tube (b) Companion cells
(c) Bast parenchyma (d) All the above
Answer: d) In phloem, sieve tube elements have thin cellulosic walls, companion cells and phloem parenchyma are simple thin walled parenchymatous cells except phloem fibres all components of phloem are living.
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