Which bone forms the lower part of the nasal septum and is also visible when the skull is viewed inferiorly?

Correct Answer: C

Rationale: The vomer, a midline bone, forms the lower nasal septum, separating the nostrils, and is visible inferiorly at the skull's base, posterior to the maxillae. The mandible is the jaw, not septal. Maxillae form the upper septum and palate, not the lower part alone. The hyoid is in the neck, not the skull. The vomer's plowshare shape and basal visibility, seen in inferior skull views, make 'c' the correct bone.

Correct Answer: B

Rationale: Pseudostratified columnar epithelium, appearing layered but single-layered with cilia, is typically in the respiratory tract (e.g., trachea), where it secretes mucus and moves debris via ciliary action. Skin has stratified squamous for protection. Stomach lining uses simple columnar for secretion/absorption. Kidney tubules feature simple cuboidal. The respiratory tract's need for mucus trapping and clearance, per tissue distribution, makes 'b' the correct location.

Correct Answer: D

Rationale: Hair's primary functions include all listed: UV protection (scalp shielding), sensory reception (via nerve endings at follicles), and insulation (trapping air for warmth), varying by location (e.g., scalp vs. eyebrows). No single role overshadows others universally scalp hair insulates, eyelashes protect, all sense. This multifunctionality, per hair's evolutionary roles, makes 'd' the correct answer.

Correct Answer: A

Rationale: Compact bone, dense and cortical, provides strength and rigidity, forming bones' outer layer (e.g., femur shaft). Spongy bone and cancellous are synonymous, porous for marrow, less strong. Cartilage is flexible, not bone. Compact bone's density, per skeletal structure, makes 'a' correct.

Correct Answer: C

Rationale: The lumbar curve, a secondary curvature, forms when a child walks, shifting weight to an upright posture, enhancing balance. Cervical forms earlier (head lifting). Thoracic and sacral are primary, fetal curves. Lumbar's development, per spinal ontogeny, makes 'c' correct.