Question

Fibres and sclereids are the types of
A. Parenchyma
B. Collenchyma
C. Sclerenchyma
D. Xylem

Answer 1

The cells are rigid, non-stretchable and are found in non-growing regions of plants, such as the bark or mature stems. Also, its cells are usually dead which have heavily thickened secondary walls containing lignin.

Complete answer:
Sclerenchyma, in plants, support tissue composed of any of various kinds of hard woody cells. Mature sclerenchyma cells are generally dead which have heavily thickened secondary walls containing lignin. The cells are also rigid and non-stretchable and are generally found in non-growing regions of plant bodies, such as the bark and mature stems. Sclerenchyma cells are found in many different shapes and sizes but two main types of cells are: fibres and sclereids.

Fibres are generally elongated cells whose long and tapering ends interlock and hence providing maximum support to the plant. They often occur in bundles and can be found anywhere in the plant body including the stem, the roots, and the vascular bundles in leaves. Many of these fibres, like seed hairs, leaf fibres, and bast fibres, are important sources of raw material for textiles and woven goods.

Sclereids are variable in shape and size. They are present in various tissues of the plant, such as the cortex, pith, xylem, and phloem. They occur in leaves and fruits also. They constitute the hard shell of nuts and the outer hard coat of many seeds. Sometimes called stone cells as sclereids are responsible for the gritty texture of pears and guavas.

Thus, the correct answer is option (C) i.e., Sclerenchyma

Note: Sclerenchyma is one of the three types of ground tissue in plants. The other two types are parenchyma (living thin-walled tissue) and collenchyma (living support tissue with irregular walls).