Which category includes bone and cartilage?

• A. Dense connective tissue proper
• B. Supporting connective tissue
• C. Liquid connective tissue
• D. Epithelial tissue

Answer: (B)

Bone and cartilage form the body's structural framework, so they’re classified as supporting connective tissue. Their main role is to provide support and protection, shaping and reinforcing the skeleton rather than covering surfaces or circulating fluids. They differ from other connective tissues in that their cells (osteocytes in bone, chondrocytes in cartilage) sit in a substantial extracellular matrix that gives rigidity: bone matrix is mineralized, making bone hard, while cartilage has a gel-like matrix with collagen that provides resilience. They also come from mesenchymal tissue. This sets them apart from dense connective tissue proper, which is rich in collagen fibers and functions mainly to connect and bind other tissues (like tendons and ligaments). Liquid connective tissue (blood/lymph) has a fluid matrix, and epithelial tissue is a cellular layer that covers and lines surfaces, not a supportive skeleton.