Protein fibers primarily come from which source?

Protein fibers primarily come from animals, which is why the correct answer is linked to this source. Animal fibers, such as wool, silk, and cashmere, are derived from living animals and are known for their unique properties, including warmth, durability, and natural resilience. These fibers are composed of proteins like keratin and fibroin, contributing to their distinctive characteristics in textile applications.

In contrast, mineral fibers, like asbestos, do not come from biological sources and are not classified as protein fibers. Plant fibers, such as cotton and linen, are derived from plant sources and are primarily composed of cellulose rather than protein. Synthetic fibers, which are produced through chemical processes, are also not derived from living organisms and do not contain protein. Hence, the identification of animal sources as the exclusive origin of protein fibers underscores the significance of biological materials in the textile industry.