Question

Which of the following statement is true?

• A. Vessels are multicellular and with wide lumen
• B. Tracheids are multicellular and with narrow lumen
• C. Vessels are unicellular and with narrow lumen
• D. Tracheids are unicellular and with wide lumen

Answer 1

The correct option is A Vessels are multicellular and with wide lumen

In higher plant xylem functions as a conducting tissue for water and minerals from roots to the stem and leaves. It also provides mechanical strength to the plant parts.
It is composed of four different kinds of elements, namely,
Vessels - These are dead long cylindrical tube-like structure made up of many cells called vessel members, each with lignified walls and a large central cavity. Vessel members are interconnected through perforations in their common walls. The presence of vessels is a characteristic feature of angiosperms and are absent in gymnosperms.
Tracheids - These are dead elongated or tube like cells with thick and lignified walls and tapering ends and a narrow cell cavity (cell cavity is larger than xylem fibres and parenchyma). In plants, tracheids and vessels are the main water transporting elements.
Xylem fibres - These are cells with highly thickened walls and obliterated central lumens that provide mechanical support.
Xylem parenchyma - These are thin-walled living cells with cell walls are made up of cellulose. They store food materials in the form of starch or fat and conduct water radially.