The schlerenchyma tissues consist of

Analyze the question: It asks what sclerenchyma tissue is made of. Sclerenchyma is a type of permanent supporting (mechanical) tissue in plants.

Explain the concept:

• Meristematic tissue is made of actively dividing, living cells at the growing points (root and shoot tips). So D is wrong.
• Parenchyma is made of living cells with thin walls, used for storage and photosynthesis.
• Collenchyma is made of living cells with walls thickened by cellulose (and pectin) at the corners. It supports young stems.
• Sclerenchyma is made of cells with walls heavily thickened with lignin. Lignin is impermeable, so the protoplasm dies when the cell matures. At maturity the cells are dead and serve only to give strength and support. There are two types: fibres (long, thin cells) and sclereids (short, stone-like cells, as in the gritty texture of pear fruit and in nut shells).

Solution:

• A. Dead cell: correct, because mature sclerenchyma cells are dead, lignified, and structural.
• B. Living cell: describes parenchyma and collenchyma, not sclerenchyma.
• C. Tracheid cell: tracheids are a type of xylem cell that conducts water. They are also dead and lignified, but they belong to xylem, not sclerenchyma. They are not the general description of sclerenchyma.
• D. Meristematic cell: these divide actively and are not specialised, so this is wrong.

Answer: A. dead cell

Tip: Remember "Sclerenchyma = Stiff and Stopped living (dead)". Collenchyma is living support tissue, and sclerenchyma is dead support tissue. When you see "lignin", think "dead cells".