Everything Life Sciences Grade 10

FACT

A useful way to

remember the

difference between

collenchyma and

sclerenchyma is to

remember the 3 Cs

pertaining to

collenchyma:

thickened at

corners, contain

cellulose, and

named

collenchyma.

Sclerenchyma

Diagram Micrograph

Figure 5.12: Sclerenchyma tis-

sue provides support in plants.

Figure 5.13: Cross-section of

sclerenchyma fibres.

Figure 5.14: Sclereid.

Sclerenchyma

Structure Function

Cells are dead and have lignified

secondary cell walls.

This provides mechanical strength and

structural support. The lignin provides a

’wire-like’ strength to prevent from

tearing too easily.

Sclereids have strong walls which fill

nearly the entire volume of the cell.

Provide the hardness of fruits like pears.

These structures are used to protect other

cells.

Sclerenchyma tissues are important components in fabrics such as flax, jute and hemp. Fibres
are important components of ropes and mattresses because of their ability to withstand high
loads. Fibres found in jute are useful in processing textiles, given that their principal cell
wall component is cellulose. Other important sources of fibres are grasses, sisal and agaves.
Sclereid tissues are the important components of fruits such as cherries, plums or pears.

Activity: Observing sclerenchyma in pears

Aim:

To observe sclerenchyma stone cells (sclereids) in pears

Materials:

• soft, ripe pear


• microscopes, microscope slides and cover slips


• iodine solution


• dissecting needles or forceps

Instructions:

Chapter 5. Plant and animal tissues 125