Final answer:
The ends of long bones, such as the femur, have a cartilage cap called articular cartilage. It provides a smooth surface for joints and helps reduce friction.
Step-by-step explanation:
The ends of long bones, such as the femur, have a cartilage cap called articular cartilage. The articular cartilage covers the rounded ends of long bones, known as the epiphyses. It provides a smooth surface for joints and helps reduce friction during movement. Additionally, the epiphyses are filled with red bone marrow, which produces blood cells.