Page 4 - 2- Lesson Notes- Simple Permanent Tissue
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(iii)Sclerenchyma
Structure
o They are dead cells, long and narrow cells, appear angular in cross section.
The cells have highly thick cell walls.
o Cells do not have intercellular spaces as the cell walls are thickened with lignin.
Lignin is like strong cement that binds the cells together. Often there is no space
and cytoplasm left in the cells.
o Present in stem, roots and in the veins of leaves. Also present in the hard seed
coat covering.
o Provide strong mechanical support, rigidity and flexibility to the plant.
Types of Parenchyma Cells
o Cells of sclerenchyma are of two types: fibres and sclereids.
o Fibres consist of very long, narrow, thick and lignified cells.
o Sclereids are irregular shaped.
