Q.Which one of the following is natural polymer?

Protein is a natural polymer; the rest are man-made (synthetic) polymers.

Natural polymers occur in nature. Proteins are natural condensation polymers of alpha-amino acids linked by peptide (amide) bonds.

• (B) Nylon-6 — synthetic polyamide. …

Protein is the only naturally occurring polymer among the options; the other three are synthetic.

Polymers are classified as natural (occurring in nature — e.g. proteins, starch, cellulose, natural rubber) or synthetic (man-made — e.g. plastics, synthetic fibres).

• Protein is a natural biopolymer, built from amino-acid monomers joined by peptide bonds, made by living organisms.
• Polyethylene is a synthetic addition polymer of ethylene. …