Question

Differences between sclerenchyma fibres and sclereids.

Answer 1

Hint: Fibres are elongated, spindle-shaped cells with pointed tips that are thick and elongated. Fibres have a small lumen with simple, spherical pits in them. Lignification occurs in the secondary cell wall. Fibres are found in the cortex, pericycle, xylem, and phloem, among other places. Fibres' primary role is to offer mechanical strength to the plant while also assisting in seed and fruit dissemination.

Complete answer:
Because of the lignin characteristics, sclerenchyma tissues provide mechanical support. Sclerenchyma fibres and sclereids are two types of sclereids. The following are the distinctions between fibres and sclereids:

SCLERENCHYMA FIBERS	SCLEREIDS
Thick, elongated, spindle shaped cells with pointed tips	Sclerenchyma cells with highly-thickened lignified cell walls having a narrow lumen
Elongated cells	Broad cells with irregular shape
Tapering end walls	Blunt end walls
Unbranched	Branched or unbranched
Originate from meristematic cells	Originate from secondary wall thickening of parenchyma cells
Generally occur in bundles	Singly or loose groups
Found in cortex, pericycle, xylem, and phloem	Found in cortex, pith, pulp of fruits, and fruit walls
Provides mechanical strength	Provides stiffness

Sclerenchyma cells are divided into two groups based on their shape: fibres and sclereids. Sclereids are created by the secondary wall thickening of parenchyma cells, while fibres come from meristematic cells. Surface fibres, xylary or wood fibres, and extraxylary or bast fibres are the three types of sclerenchyma fibres.

The seed coat (coconut) and the fruit wall include surface fibres. Wood fibres, also known as xylary, are found in the xylem. Extraxylary or bast fibres — Cortex, pericycle, and phloem are all associated with extraxylary or bast fibres.

Sclerenchyma cells with thick lignified cell walls and a restricted lumen are referred to as sclereids. They can be found in the cortex, pith, pulp, and fruit walls. Macrosclereids, osteosclereids, astrosclereids, and brachysclereids are the four primary types of sclereids.


Note:-
Sclereids are wide cells, while fibres are elongated cells. Fibres and sclereids are both sclerenchyma cells having a thick, lignified secondary cell wall. The form of the cells is the fundamental distinction between fibres and sclereids. Sclerenchyma is referred to as a "dead tissue" because the cells have thick lignified secondary walls that often die once they have developed and stopped elongating.