Synovial joints differ from the other types of joint between bones in the body because:

Correct Answer: D

Rationale: Synovial joints are freely movable, with hyaline cartilage on bone ends reducing friction (unlike fibrous or cartilaginous joints). A and B are wrong types, C is cartilaginous. Answer is D, per the document.

Correct Answer: A

Rationale: The symphysis pubis (cartilaginous) is slightly movable (amphiarthrotic). Sutures are immovable, elbow/shoulder are synovial (freely movable). Answer is A, per the document.

Correct Answer: A

Rationale: The xiphoid process is the inferior tip of the sternum, not humerus, temporal (mastoid/styloid), or tibia. Answer is A, per the document.

Correct Answer: C

Rationale: An osteon is a cylindrical unit of compact bone with concentric lamellae around a Haversian canal, not spongy bone, membrane, or bone end. Answer is C, per the document.

Correct Answer: D

Rationale: Bones’ strength comes from calcium and phosphorus in hydroxyapatite, forming a hard matrix. Silica is minimal, cartilage is flexible, blood/marrow fill spaces—not strength sources. 'Calcium and phosphorous' is correct.