Which of the following is NOT among the six tissues with greater protein density?

• A. Tendon
• B. Ligament
• C. Cartilage
• D. Fascia

Answer: (C)

Protein density in tissues is driven by how much protein, especially collagen, is packed into the tissue. Tendon, ligament, and fascia are dense connective tissues with tightly packed collagen fibers, giving them very high protein density and strong tensile properties. Cartilage, while it contains collagen, has a matrix dominated by proteoglycans and water, so its dry protein content is lower compared with these dense connective tissues. Because of this matrix makeup, cartilage does not rank among the tissues with the highest protein density. That’s why cartilage is not part of the six tissues with greater protein density.