Concept : Joints : Joints play an important role in the skeletal system as it allows different types of movement at different locations. If the skeleton is without joints, then there would be no movement in the human body. An adult body consists of 206 bones. Explanation : A joint is a connection that occurs between the bones in the skeletal system. The joints provide the means for movement. The joints help us to rotate our shoulders, bend our knees and elbows, and move our necks. Ball and socket joint : This type of joint helps in rotatory movement. One bone is hooked into the hollow space of another bone. Examples: shoulders Pivotal joints : This type of joint in sideways and back forth movement. One bone has tapped into the other in such a way that full rotation is not possible. Example: Pivotal joint in the neck Hinge joints : Hinge joints are like hinges in the door, where only back and forth movement is possible. Examples are ankle, elbows, and knee joints. Fixed joints : In this type of joint bones are fused together in such a way that they are anchored to the component, mostly to form a fixed structure. Examples are the skull and upper jaw​​ ​So, the correct answer is : Ball and socket joint - Arms and shoulders Pivotal joint - neck Hinge joint - elbow Fixed joint - jawAdditional Information Gliding joint : This joint allows two or more round or flat bones to freely move or slide together without rubbing. Examples are the wrist, palm, ankle, and sole Saddle joint : This type of joint does not allow rotation, it does not allow for back and forth movement as well as side to side movement. Example : Thumb