Dead, elongated with tapering end . Vessels: Made of row of dead cells . Xylem fibres: Lignified and sclerenchymatous. .
Xylem parenchyma: Living and cellulosic Phloem: Food conducting tissue . Sieve elements: Sieve cells & sieve tubes . Companion cells: Only in Angiosperms. .
Phloem parenchyma: Living & absent in Monocots. . Phloem fibres: Thick walled & sclerenchymatous, giving mechanical strength. Fibres: .
Wood fibres: xylary fibres . Bastfibres: Extra xylary fibres . Surface fibres: Cottan . Mesocarp fibres: Coconut .
Leaf fibres: Agave Complex tissues: More than one type of cells. Concept Map Syncyte: Cell which is formed by fusion of cells is called Syncyte. Example: Vessels (Dead syncyte), sieve tube (living syncyte) and ray parenchyma. They are present in Pteridophytes,Gymnosperms and Dicots.
Phloem Fibres (or) Bast Fibres The fibres of sclerenchyma associated with phloem are called phloem fibres or bast fibres. They are narrow, vertically elongated cells with very thick walls and a small lumen. Among the four phloem elements, phloem fibres are the only dead tissue. These are the strengthening as well as supporting cells.
Table . : Different types of tissues Distribution Main functions Nature Cell shape Wall materials Parenchyma Cortex, Pith medullary rays and Packing tissues in vascular system Packing tissue, support, gaseous exchange, food storage Living Usually Isodiametric Mainly Cellulose and Pectin Collenchyma Outer region of cortex as in angles of stems, mid-rib of leaves Mechanical Living Elongated, Polygonal Mainly Cellulose, Pectin and Hemi- cellulose Sclerenchyma (a) Fibre Outer region of cortex, pericycle of stems, vascular bundles Mechanical Dead Elongated and Polygonal with tapering ends Mainly Lignin (b) Sclereids Cortex, Pith, Phloem shells and stones of fruits and seed coats Mechanical Protection Dead Roughly Isodiametric with much variation Mainly lignin Tracheids and Vessels Vascular System Translocation of water and mineral salts Dead Elongated and Tubular Mainly lignin Phloem Sieve tubes Vascular System Translocation of organic solutes Living Elongated and Tubular Cellulose, Pectin and Hemicellulose Companion Cells Vascular System Work in association with sieve tubes Living Elongated and narrow Cellulose, Pectin and Hemicellulose Difference Between Meristematic Tissue and Permanent Tissue