Write any two differences between plant and animal fibres ?
Animal fibers like silk or wool are made of proteins.
Wool is keratin and silk from silk worms is fibroin and sericin. The fibroin fiber is not a simple repeat of two or three amino acids it is a complex zigzag chaining sequence containing nearly 20 amino acid residues in it.
Plant fibers are mainly cellulose. Cellulose is not protein it is actually glucose sugar molecules polymerized into long chains. Single molecules of glucose can be knitted together in polymers like starch or cellulose with extremely different characteristics despite being built up from the same subunit. The plant can embed them in soluble pectins and crosslink them with lignins to produce a basis for woody materials. Plants further lay down the fibers in different architectures.