Fibre origin: which of the following is a natural fibre/material based on a naturally occurring polymer?

Introduction / Context:
Distinguishing natural from synthetic fibres is foundational in materials selection. Natural fibres derive from polymers produced by biological systems, while synthetic fibres come from man-made polymerisation routes.

Given Data / Assumptions:

• Cellulose is the structural polysaccharide found in plant cell walls.
• Dacron is the trade name for PET (polyethylene terephthalate) fibre.
• Nylon-6 is a synthetic polyamide (polycaprolactam).

Concept / Approach:
Cellulose is a natural polymer built from glucose units via beta-1,4-glycosidic bonds, forming fibres such as cotton and flax. Dacron and nylon-6 are fully synthetic polymer fibres produced through controlled industrial polymerisation and spinning processes. Therefore, the natural material among the options is cellulose.

Step-by-Step Solution:
Classify cellulose → natural polysaccharide; source of natural fibres (cotton, linen).Classify Dacron → PET (synthetic polyester).Classify nylon-6 → synthetic polyamide (PA6).Select cellulose as the natural entry.

Verification / Alternative check:
Textile references list cellulose-based fibres as “natural fibres,” while PET and nylon are “man-made” or “synthetic” fibres, sometimes “regenerated” for viscose/rayon but still derived through processing.

Why Other Options Are Wrong:
Dacron: synthetic polyester.Nylon-6: synthetic polyamide.None of these: incorrect because cellulose qualifies.

Common Pitfalls:
Confusing “cellulose acetate” (regenerated/derivative) with natural cellulose; forgetting that trade names often obscure chemistry.

Final Answer:
Cellulose