Question 3
Coir, hemp fibre and cotton thread are all made of which cell type?
The right answer is the one marked above.
Sclerenchyma fibres. Long narrow dead cells with thick lignified walls, lying in bundles — which is exactly what makes a rope strong when pulled along its length.
Sclereids are the other sclerenchyma cell type: short, irregular and very thick-walled, found in a coconut shell or the gritty flesh of a pear.