The structural classification of joints is based on the composition of the binding material and the presence or absence of a joint cavity. true or false

True

Explanation:

A joint is a point of connection between two or more bones in the body, linking the skeletal system into a whole functional system. Joints can be classified structurally depending on the composition of the binding material and the presence or absence of a cavity at the joint.

Classification of joints, according to the material the joint is composed of, and the absence of joint cavity, include:

1. Fibrous Joints: The bones in this type of joints are held together by a dense, tough connective tissue. This fibrous tissue is rich in collagen fibers. There is absence of cavity in this joint.

2. Cartilaginous Joints: Bones in this joint are connected by hyaline cartilage or fibrocartilage. They have no joint cavity.

3. Synovial Joints: These joints have a cavity called the synovial cavity which is filled with synovial fluid.

i'd say that the moon rock is about 2.2 billion years old.