Question

Epidermal hair of ________ seed coat is commercially useful.
a. Coconut
b. Cotton
c. Jute
d. Sun hemp

Answer 1

Hint: Epidermis is the single layer, in which every single cell of the epidermis outgrowth the hair-like structure called fiber, and this hair are usually outgrown of the seed coat, and some epidermal hairs are long in length, while some hairs stop growing from themselves, and they called as fuzzy hair.

Complete answer:
- Out of all hairs of seed coats given in the above question, cotton hairs are more commercially used.
- Cotton fiber is economically very important, because in the world the most commonly used textile is cotton and it is a product of half the textile industries of the world.
- While the fibers produced by the cotton are not exactly the cotton because they are present as actual fiber structures, instead they are called trichomes.
- This is because the fiber walls of cotton are not lignified, and it does not actually possess the true characteristic features of fibers.
- Each seed contains 10,000 to 20,000 hairs, and the ripen hairs can twist and cling and are useful for spinning and unripe hair. They are very thin, have less strength and they have less value.
- When it comes to the other options such as coconut, jute, sun hemp, where the fibers are of non-epidermal origin, they are not epidermal hairs, while fibers are present in the stem, and they resemble the try fibers.
- So the correct option for the above question is cotton.
- Components of the cotton seeds hair are
90% cellulose.
7 to 8% water. 0.4% wax, 0.6% nitrogenous matter and 1% mineral matter.

Hence, the correct answer is option (B).

Note: Commercial uses of cotton hair includes that, lint hairs of the cotton is usually spun into threads, for making the cotton cloths, while fuzz hair of cotton seeds are used for making cotton bathing and rayon and other types of plastic and as other commercial products.