Question

In xylem, fibre gives strength to
A. Vessels
B. Tracheids
C. Parenchyma
D. Storage tissue

Answer 1

Hint: Xylem fibre is present in between vessels and tracheids of the xylem tissue. It is made up of dead sclerenchyma cells and they provide mechanical strength to the tissue and are responsible for the upward transportation of the materials.

Complete Answer:
On the basis of the origin of the xylem tissues, it can be categorized into two main types: primary xylem and secondary xylem. Primary xylem tissues originate from procambium and secondary xylem tissues come from vascular cambium.

There are different elements present in the xylem tissues:
1. Tracheids: They are primitive conducting, tube-like and dead cells having tapered ends. These cells lack in protoplast and these structures are generally found in the gymnosperms and lower angiosperms. So, these are mainly involved in the transportation process.
2. Vessels: They are long and cylindrical in shape cells having tube-like structure. The walls of the tissues are highly lignified and at the centre there is a large cavity and these cells are also dead and lack protoplasm. These are involved in the transportation of water and minerals. These are mainly found in the angiosperms and they give strength to the plants.
3. Xylem fibre: These are dead cells having lignin content and central cavity. Help in the transportation and provide mechanical strength to the plants.
4. Xylem parenchyma: These are the only living cells present in the xylem. They store starch and fat in them. These cells help in the transportation of materials in short distances.

Thus, we can conclude that xylem fibres provide strength to the vessels and option ‘A’ is the correct option.

Note: Xylem is the tissue responsible for the transportation of water and minerals from the roots of the plant which is absorbed by roots from the soil, to all other parts of the plant body like flower, stem and leaves.