Question

A mature sieve tube differs from vessel in:

• A. Being nearly dead
• B. Lacking cytoplasm
• C. Lacking a functional nucleus
• D. Absence of lignified walls

Answer 1

The correct option is D Absence of lignified walls

Vessels are the components of xylem, while sieve tubes are present in phloem tissue. The walls of the vessel are lignified i.e., they are made up of lignin. They are extremely hard but not thick. Sieve tube on the other hand, posseses thin cellulosic wall.