Question

Which of the following is a surface fibre?
A. Flax
B. Cotton
C. Sunn hemp
D. Manila hemp

Answer 1

Hint: Surface fibres are the natural fibres. Surface fibres are found on the covering of seed, leaves or fruits. They are economically very important.

Complete Answer:
Fibres are long, tapering cells which die at maturity. It is mostly composed of cellulose and lignin. It is used to make fabrics. They can be obtained from both the plant and animal sources. Plant sources include jute, cotton. Animal sources include wool from the sheep, silk from silkworm.

Types of plant fibres-
1. Soft or bast fibres—They are found in the inner bark of dicot stems. Flax used for making linen, jute, sunn hemp is the example of bast fibres.
2. Hard or leaf fibres—They are extracted from the monocot leaf vascular bundles. Manila hemp is an example of hard fibre.
3. Surface fibres-They grow from the surface of seeds, leaves or fruits. Cotton is a surface fibre extracted from the covering of seed.

The correct answer is (B). Cotton is a surface fibre.

Additional Information: Coconut is another example of surface fibre which is obtained from the fruit of coconut. It is used to make mats, ropes. They have high tensile strength.

Note: Cotton is a soft fibre that grows in a ball around the cotton seed. It is made up of cellulose. The cotton balls are an adaptation for seed dispersal. It is widely used to make cotton fabrics. Sunn hemp is three times stronger than cotton fibres.