Which animal fiber is strong and resilient but leaves water marks and degrades from age and sun?

Which animal fiber is strong and resilient but leaves water marks and degrades from age and sun?

• A. Silk
• B. Cotton
• C. Wool
• D. Rayon

Answer: (A)

Animal fibers vary a lot in how they behave under moisture and light. Silk, produced by silkworms, is exceptionally strong and resilient for a natural fiber, which is why it feels sturdy and holds shape well. At the same time, silk is a protein-based fiber that is sensitive to moisture and UV light. When silk gets wet, it can dry with uneven absorption or dye migration, leaving visible water marks on the fabric. And over time, exposure to the sun's rays breaks down the silk proteins, causing yellowing, weakening, and a loss of strength. These combined traits—great strength and resilience, plus vulnerability to water spots and aging from sun exposure—make silk the best fit for the description. Cotton and rayon aren’t animal fibers, and wool, while strong, doesn’t typically be described by water marks in the same way and ages differently under sun.

Animal fibers vary a lot in how they behave under moisture and light. Silk, produced by silkworms, is exceptionally strong and resilient for a natural fiber, which is why it feels sturdy and holds shape well. At the same time, silk is a protein-based fiber that is sensitive to moisture and UV light. When silk gets wet, it can dry with uneven absorption or dye migration, leaving visible water marks on the fabric. And over time, exposure to the sun's rays breaks down the silk proteins, causing yellowing, weakening, and a loss of strength. These combined traits—great strength and resilience, plus vulnerability to water spots and aging from sun exposure—make silk the best fit for the description. Cotton and rayon aren’t animal fibers, and wool, while strong, doesn’t typically be described by water marks in the same way and ages differently under sun.