NEET BIOLOGY

Detailed explanation-1: -There are two types of sclerenchyma (Figure 4.4): (1) fibers, which are long, very narrow cells with sharply tapering end walls; and (2) sclereids, which are isodiametric to irregular or branched in shape. Fibers function in mechanical support of various organs and tissues, sometimes making up the bulk of the tissue.

Detailed explanation-2: -Surface fibres, xylary or wood fibres, and extraxylary or bast fibres are the three types of sclerenchyma fibres.

Detailed explanation-3: -Sclerenchyma fibres (Phloem fibres) are present in Metaphloem and usually absent in Protophloem. However, Protophloem can sometimes contain specialized phloem fibres.

Detailed explanation-4: -Sclerenchyma Fibres Surface fibres: found on fruit wall and seed coat (e.g., coconut) b. Xylary or Wood fibres: associated with xylem.

Detailed explanation-5: -Mature sclerenchyma cells are usually dead cells that have heavily thickened secondary walls containing lignin. The cells are rigid and nonstretchable and are usually found in nongrowing regions of plant bodies, such as the bark or mature stems.