The main difference between fibres and sclereids is that fibres are unbranched, elongated cells whereas sclereids are short, isodiametric or irregular cells that may be branched or unbranched. Moreover, fibres have tapering end walls while the end walls of the sclereids are blunt.
Fibres and sclereids are two types of sclerenchyma cells that differ in shape. Fibres originate from meristematic cells while sclereids are formed by the secondary wall thickening of parenchyma cells.
Key Areas Covered
1. What are Fibres
– Definition, Shape, Function
2. What are Sclereids
– Definition, Shape, Function
3. What are the Similarities Between Fibres and Sclereids
– Outline of Common Features
4. What is the Difference Between Fibres and Sclereids
– Comparison of Key Differences
Aastrosclereids, Brachysclereids, Fibres, Macrosclereids, Oosteosclereids, Parenchyma, Sclereids, Sclerenchyma, Xylem
What are Fibres
Fibres are thick, elongated, spindle-shaped cells with pointed tips. The lumen of fibres is narrow and contains simple, rounded pits. The secondary cell wall is lignified. Typically, fibres occur in the cortex, pericycle, xylem, and phloem. The main function of fibres is to provide the mechanical strength to the plant while aiding in the dispersal of seeds and fruits.
The three types of sclerenchyma fibres are surface fibres, xylary or wood fibres, and extraxylary or bast fibres.
- Surface fibres – Found in the seed coat (coconut) and fruit wall
- Xylary or wood fibres – In the xylem
- Extraxylary or bast fibres – Associated with cortex, pericycle, phloem
What are Sclereids
Sclereids refer to the sclerenchyma cells with highly-thickened lignified cell walls with a narrow lumen. They occur in the cortex, pith, pulp of fruits, and fruit walls. The four main types of sclereids are macrosclereids, osteosclereids, astrosclereids, and brachysclereids.
- Macrosclereids – Rod-like sclereids found in the bark and the seed coat of the legumes
- Osteosclereids – Bone-like sclereids with lobed ends; found in seed coat and fruit wall
- Astrosclereids – Star-shaped sclereids found in dicot leaves and gymnosperms
- Brachysclereids – Isodiametric sclereids found in the cortex, pericarp of the coconut shell, pith; also called stone cells. Numerous stone cells present in the pulp of the fruit are called the grit cells.
Similarities Between Fibres and Sclerenchyma
- Fibres and sclereids are two types of sclerenchyma cells found in plants.
- They are simple tissues that are nonliving.
- The main function of both cells is to provide structural support to the plant.
- The walls of both types of cells are thickened by the deposition of lignin.
- Sclerenchyma cells occur in the hypodermis, vascular regions, cortex, stem, leaves, and fruit walls.
Difference Between Fibres and Sclereids
Fibres: Thick, elongated, spindle-shaped cells with pointed tips
Sclereids: Sclerenchyma cells with highly-thickened lignified cell walls having a narrow lumen
Fibres: Elongated cells
Sclereids: Broad cells with irregular shape
Fibres: Tapering end walls
Sclereids: Blunt end walls
Sclereids: Branched or unbranched
Fibres: From meristematic cells
Sclereids: By the secondary wall thickening of parenchyma cells
Fibres: Generally occur in bundles
Sclereids: Singly or loose groups
Fibres: Cortex, pericycle, xylem, and phloem
Sclereids: Cortex, pith, pulp of fruits, and fruit walls
Fibres: Provides mechanical strength
Sclereids: Provides stiffness
Fibres are elongated cells while sclereids are broad cells. Both fibres and sclereids are sclerenchyma cells with a thick, secondary cell wall that is lignified. The main difference between fibres and sclereids is the shape of the cells.
1. “Different Types of Sclerenchyma -Fiberes and Sclereids and Their Function.” Difference between Dicot and Monocot Embryo, Available Here
1. “Botana curus X dicot fibres 400×” By Kelvinsong – Own work (CC BY 3.0) via Commons Wikimedia
2. “Stone cells in Pyrus pear” By Berkshire Community College Bioscience Image Library (Public domain) via flickr
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