What type of joint allows for rotation in addition to bending and straightening?

The ball-and-socket joint is specifically designed to provide a wide range of motion, allowing for rotation as well as bending and straightening. This type of joint is exemplified in the human body by the shoulder and hip joints. The rounded end of one bone fits into the concave socket of another bone, creating a structure that permits movement in multiple directions, including circular motion.

In contrast, the hinge joint, such as the elbow or knee, primarily allows movement in one direction, enabling bending and straightening but not rotation. The pivot joint, found at the neck between the first and second cervical vertebrae, allows for rotational movement around a single axis but does not facilitate bending or straightening. Immovable joints, as their name implies, do not permit any movement at all, further differentiating them from joints that allow for bending, straightening, or rotation. Thus, the ball-and-socket joint’s unique structure and function make it the correct choice for this question.