AP BIOLOGY

Detailed explanation-1: -Commercially useful bast fibres include flax, hemp, jute, kenaf, ramie, roselle, sunn, and urena. See also list of plant fibres. Fibre bundles are often several feet long and composed of overlapping cellulose-rich sclerenchyma cells and a cohesive gum, or pectin, which strengthens plant stems.

Detailed explanation-2: -There are two types of sclerenchyma cells: fibers and sclereids. Both types have secondary cell walls that are thickened with deposits of lignin, an organic compound that is a key component of wood. Fibers are long, slender cells; sclereids are smaller-sized. Sclereids give pears their gritty texture.

Detailed explanation-3: -The main function of sclerenchyma is to provide mechanical support and strength to the plants. They provide structural support to the plant organs. They form protective coverings around nuts and seeds. They are also a part of vascular bundles and form conductive tissues.

Detailed explanation-4: -Sclerenchyma is a plant tissue providing mechanical stiffness and strength. Fibres and sclereids are the main types of sclerenchyma cells. Most sclerenchyma cells show intrusive growth. The cell walls of sclerenchyma have thickened secondary layers made from cellulose, hemicelluloses and lignin.

Detailed explanation-5: -The cells of sclerenchyma are long and narrow and thickened because of the presence of lignin.