Final answer:
The part of the rib that makes the sternochondral joint is composed of costal cartilage.
Step-by-step explanation:
The part of the rib that makes the sternochondral joint is composed of costal cartilage. Costal cartilage is a type of hyaline cartilage that extends from the rib and attaches to the sternum, either directly or indirectly. It provides for the attachment of most ribs to the sternum.