What is the primary function of the skeletal system?

Correct Answer: D

Rationale: The skeletal system's primary functions include all: hormone production (e.g., osteocalcin from osteoblasts), blood cell production (marrow in long bones), and protection/support (e.g., skull, rib cage), a comprehensive role. No single function excludes others bones multitask. This broad scope, per skeletal physiology, makes 'd' correct.

Correct Answer: B

Rationale: The hyoid bone, free-floating in the neck, anchors tongue and larynx muscles (e.g., genioglossus), aiding speech/swallowing. It doesn't support the skull , protect thorax , or form skull base (d, occipital). Its muscular role, per anatomy, makes 'b' correct.

Correct Answer: D

Rationale: Paranasal sinuses (frontal, maxillary, etc.) warm/humidify air , produce mucus to trap debris, and lighten the skull (not a, reducing weight). All functions apply, enhancing respiration and skull structure, making 'd' correct.

Correct Answer: D

Rationale: Metabolism is the sum of all chemical reactions in an organism, including catabolism (breaking down) and anabolism (building up), powering life processes like growth. Adjustment to changes is homeostasis, not metabolism. Cell specialization is differentiation, new cell formation is regeneration distinct processes. Metabolism's comprehensive chemical scope, per physiology, makes 'd' correct.

Correct Answer: C

Rationale: The midsagittal plane divides the banana (or body) into equal right and left halves lengthwise, matching the split's vertical, midline cut. Coronal splits front-back, longitudinal is vague (often sagittal), transverse cuts horizontally. Midsagittal's symmetry, per planes, makes 'c' correct.