Question

Cell wall of sclerenchymatous fibres and sclereids are respectively thickened by?

• A. Lignin, lignin
• B. Lignin, cellulose
• C. Cellulose, hemicellulose
• D. Cellulose, cellulose

Answer 1

The correct option is A

Lignin, lignin

The correct option is A.

The explanation for the Correct option:

1. The cell wall of sclerenchymatous fibres and sclereids are thickened by lignin.
2. Mature sclerenchyma cells are generally dead cells that have heavily thickened secondary walls composed of high content of lignin.
3. Sclerenchyma cells are in many different shapes and sizes.
4. Two main types are fibres and sclereids.
5. Fibers are elongated and they are thick-walled pointed cells.
6. Sclereids are heavily thickened dead cells.
7. Their shape can be spherical, oval, or cylindrical having tapered cavities called the lumen.

The explanation for Incorrect options:

Option B:

The cell wall of sclerenchymatous fibres and sclereids both are thickened by lignin, not cellulose.

Option C:

The deposition of lignin causes the thickening of the cell wall of sclerenchymatous fibres and sclereids, not cellulose and hemicellulose.

Option D:

The cell wall of sclerenchymatous fibres and sclereids both are thickened by lignin, not cellulose.

Final answer: Cell wall of sclerenchymatous fibres and sclereids are respectively thickened by lignin.