Question

Long, pointed sclerenchyma cells are:
A. Fibres
B. Tracheids
C. Wood parenchyma
D. Sclereids

Answer 1

Hint: We all know that plant tissues are of two types: meristematic and permanent. The permanent tissues are those which have lost their ability to multiply. Sclerenchyma is one such permanent tissue. Even Sclerenchyma is further divided into fibres and stones according to their shapes.

Complete answer:
To solve the given question, we must be well aware of the sclerenchyma.
The permanent tissues are divided into:
> Simple Permanent Tissue
> Complex Permanent Tissue
Sclerenchyma is a type of simple permanent tissue. They have thick walls due to the deposition of lignin on their cell wall.
Sclerenchyma now we know is again of two types:
> Fibres
> Sclereids
Fibres are elongated thick walled cells which have pointed ends. Since they have very thick cell walls due to the deposition of lignin, they have very narrow lumen. Like all sclerenchyma cells, these are also dead cells. Their main function is to provide mechanical support to the plant body.
Sclereids or stone cells are isodiametric but some of them may also be elongated. They are very hard and might be present in the pith and the cortex of the gymnosperms.

Therefore, the correct answer to the question is fibres.

Note: The fibres are also of two types: xylem fibres and bast fibres. The xylem fibres arise from the meristematic cells which also give rise to the xylem. Bast fibres include phloem fibres, perivascular fibres, and the cortical fibres.