Ligaments are very strong but resistant to stretch. Which protein fiber most likely predominates in their structure?

• A. Collagen fibers
• B. Keratin fibers
• C. Elastic fibers
• D. Reticular fibers

Answer: (A)

Verified step by step guidance

1. Understand the function of ligaments: Ligaments connect bones to other bones and provide stability to joints. They are designed to resist stretching and maintain structural integrity under tension.
2. Review the properties of protein fibers: Collagen fibers are known for their tensile strength and resistance to stretching, making them ideal for structures like ligaments. Elastic fibers allow tissues to stretch and recoil, keratin fibers are found in skin and hair, and reticular fibers form supportive networks in soft tissues.
3. Match the properties of ligaments to the protein fiber: Since ligaments are strong and resistant to stretch, the predominant protein fiber must have high tensile strength and low elasticity. This aligns with the properties of collagen fibers.
4. Eliminate incorrect options: Keratin fibers are not found in ligaments, elastic fibers are too stretchy for ligament function, and reticular fibers are not designed for tensile strength. Collagen fibers are the most suitable choice.
5. Conclude the reasoning: Based on the structural and functional requirements of ligaments, collagen fibers are the predominant protein fiber in their composition.