Question

What are Bast fibers?
A.Stem fibers
B.Fruit fibers
C.Leaf fibers
D.Synthetic fibers

Answer 1

Hint: Bast fiber is a flexible strong fiber which is collected from the bast surrounding the stem of certain plants. It is a type of cellulose fiber which is quite soft and strong. It is obtained from the stems of dicotyledonous plants which are basically flowering, net-veined leaves plants.

Complete step by step answer:
Bast fibers are also known as soft fibers which are used in carpets, ropes, textiles, etc. These are quite fine and flexible fibers. Flax, jute, kenaf are some commercially useful bast fibers. The bundles of fibers are several feet long and are composed of pectin which is a cohesive gum that strengthens plant stems. The location of fibers is in between the epidermis. These are present surrounding the stems of the plants so these are known as Stem fibers.

So, the correct choice is (A).

Additional Information: Bast fibers are freed from the stalk by the process of retting. Retting is a process in which the microorganisms and moisture in plants dissolve the excess of cellular tissues and the pectin present around the bundles of bast fibers for their easy removal from the stem.
Bast fibers are stronger and available at low cost. These fibers are biodegradable and can also be recycled. Bast fibers are fine in texture with efficient length. The quality of fibers depends on the seed selection, growing methods, location, fertilization and separation techniques. Hemp and Kenaf are coarse in texture, Flax is fine and Ramie is very fine in texture.

Note:
Leaf fibers come under the hard fiber group which is less flexible. These are mainly used for producing rope. Synthetic fibers are made from synthetic polymers of small molecules. Petrochemicals are used to make such fibers. These are man- made fibers like nylon, polyester, rayon, spandex, etc. Bast fibers lack in moisture absorption due to which they can also be hybridized with synthetic fibers to attain better properties.