. A mature sieve tube differs from a vessel

A: In lacking a functional nucleus

B: Absence of lignified walls

C: Being nearly dead

D: Lacking cytoplasm

Best Answer

Explanation :

  • A mature sieve tube is a stack of vertical cells and its lateral walls have perforated sieve plates because it serves as phloem’s main conducting element.
  • It does not have lignin in its wall.
  • And they retain protoplast during differentiation but nucleus is absent.
  • While vessels are dead elements of xylem that conducts water. It lacks nucleus and cytoplasm.
  • Vessel’s secondary walls are thick because of lignin deposition.

Final Answer :

Hence, the correct option is B, i.e. Absence of lignified walls.

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