Correct option is B
The correct answer is (b) Collenchyma cells are rigid.
Collenchyma cells are not rigid; they are flexible and provide structural support to growing parts of the plant such as young shoots and leaves. The flexibility of collenchyma is due to its unevenly thickened cell walls made of pectin and cellulose, which allow the cells to adapt to mechanical stress and provide tensile strength without rigidity.
In contrast, sclerenchyma cells are rigid and provide support to mature plant parts due to lignified walls.
Information Booster:
- Collenchyma structure: Cells have thickened walls composed of pectin and cellulose, providing flexibility.
- Location: Found in growing regions such as shoot tips, young stems, and petioles.
- Function: Provides support and elasticity to plant parts, enabling them to withstand bending and stretching.
- Presence in roots: Rarely found in subterranean parts due to limited mechanical stress in those areas.
- Differences from sclerenchyma: Sclerenchyma is rigid and lignified, whereas collenchyma is flexible and non-lignified.
Additional Knowledge:
(a) Collenchyma cell walls are thick, and they require more glucose for their production:
This is correct. Collenchyma cells have thickened primary cell walls rich in cellulose and pectin, which require significant energy and glucose during production.
(b) Collenchyma cells are rigid:
This is incorrect. Collenchyma cells are characterized by their flexibility and ability to stretch, allowing young plant parts to grow while still providing structural support.
(c) Collenchyma is usually produced in shoot tips and young petioles:
This is correct. Collenchyma is commonly found in actively growing regions of the plant, where support and flexibility are needed.
(d) Collenchyma is generally not present in subterranean shoots and roots:
This is correct. Collenchyma is absent in underground parts like roots, as they do not require the same flexibility and mechanical support as above-ground parts.
