Final answer:
The flexibility of bones depends on their joint structure and movement. Joints that allow for wide ranges of motion are less stable but provide greater mobility, while stable joints allow for little or no movement between bones but provide stability and support.
Step-by-step explanation:
The flexibility of bones depends on their joint structure and movement. Joints that allow for wide ranges of motion have articulating surfaces of the bones that are not directly united to each other, but instead enclosed within a space filled with lubricating fluid.
These joints provide greater mobility, but are less stable. On the other hand, stable joints that provide little or no movement between bones are joined together by fibrous connective tissue or cartilage, providing stability and weight-bearing support for the body.