Given a scientific passage and an answer, generate a question for the given answer.

Ex Input:
Passage: Classification of Joints on the Basis of Function The functional classification divides joints into three categories: synarthroses, amphiarthroses, and diarthroses. A synarthrosis is a joint that is immovable. This includes sutures, gomphoses, and synchondroses. Amphiarthroses are joints that allow slight movement, including syndesmoses and symphyses. Diarthroses are joints that allow for free movement of the joint, as in synovial joints. Answer: synarthrosis

Ex Output:
What category of joints is immovable?

Ex Input:
Passage: Figure 6.11 The frictional force supplies the centripetal force and is numerically equal to it. Centripetal force is perpendicular to velocity and causes uniform circular motion. The larger the F c , the smaller the radius of curvature r and the sharper the curve. The second curve has the same v , but a larger. Answer: centripetal force

Ex Output:
What force is perpendicular to velocity and causes uniform circular motion?

Ex Input:
Passage: Sex-linked traits are located on genes on the sex chromosomes. Answer: sex

Ex Output:
Sex-linked traits are located on genes on what chromosomes?