Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Immovable joints do not allow the bones to move at all. In these joints, the bones are fused together by very tough collagen. Examples of immovable joints include the joints between bones of the skull. You can see them in Figure below . Answer: immovable joints
A:
The joints that are between the bones that make up the skull are what kind of joints?