Final answer:
Cartilage is the part of the skeletal system that protects bones from wearing each other down by providing a smooth and flexible covering at the joints.
Step-by-step explanation:
Cartilage is the specific component of the skeletal system that protects bones from wearing each other down at the joints. It is a type of dense connective tissue, made up of tough protein fibers. Cartilage is known for being strong, flexible, and smooth, which makes it the ideal material to cover the ends of bones, enabling them to move smoothly over one another. It is different from muscles, tendons, and ligaments, which have other functions such as facilitating movement, connecting bones to muscles, and holding bones together, respectively.
Therefore, the correct answer to the question, 'What protects bones and prevents them from wearing each other down?' is option 2) Cartilage.
In summary, while ligaments hold bones together at joints and muscles are responsible for moving the skeleton, it is the cartilage that provides the necessary cushioning between bones to prevent wear and tear.