Lignified elongated dead cells are _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(a) Parenchyma

(b) Collenchyma

(c) Sclerenchyma

(d) None of these

Sclerenchyma is a type of permanent tissue made up of elongated, dead cells with thick, rigid walls due to lignin deposits. These cells lack intercellular spaces. Sclerenchyma is found in the coverings of seeds and nuts, around vascular tissues in stems, and in the veins of leaves. Its main role is to provide strength and rigidity to the plant. Since the cells are hard and non-stretchable, they are usually present in non-growing regions like bark and mature stems.

Sclerenchyma cells occur in various shapes, but two main types are:

1. Fibres – Long, narrow cells with tapering ends that interlock, giving maximum support.
2. Sclereids – Irregularly shaped cells found in tissues such as the periderm, cortex, pith, xylem, and phloem.

For comparison:

• Parenchyma consists of thin-walled, flexible, living cells with intercellular spaces. They form ground tissue and pith, and their shape varies with function.
• Collenchyma consists of living, elongated cells with unevenly thickened walls (made of cellulose and pectin). Found in the margins of stems and leaves, they provide flexibility and mechanical support.

Correct Answer: Sclerenchyma