Which skin layer contains blood vessels and nerves?

Correct Answer: B

Rationale: The dermis, beneath the epidermis, contains blood vessels (for nutrition), nerves (for sensation), and glands, supporting skin function. The epidermis is avascular, lacking vessels/nerves. The hypodermis has some vessels but is mainly fat. Stratum corneum , the epidermis's top, is dead cells. The dermis's vascular and neural richness, per skin anatomy, makes 'b' correct.

Correct Answer: C

Rationale: The sternum, or breastbone, is part of the axial skeleton, anchoring ribs to protect thoracic organs. Humerus and femur are appendicular (limbs). Scapula is pectoral girdle, appendicular. Sternum's axial role, per skeletal framework, makes 'c' correct.

Correct Answer: B

Rationale: The temporal bone houses the middle ear (e.g., ossicles), facilitating hearing/balance, via its petrous portion. It protects the brain partially, but ear housing is primary. Cheekbone is zygomatic, spine support is vertebral. Temporal's auditory role, per skull, makes 'b' correct.

Correct Answer: C

Rationale: The skull is axial, not appendicular, which includes limbs and girdles (humerus , clavicle , femur ). Skull's midline role contrasts with appendicular's limb focus, per skeletal division, making 'c' correct.

Correct Answer: A

Rationale: Cancer cells lack differentiation, remaining unspecialized and 'generic,' unlike normal cells (e.g., liver cells) with specific roles, driving uncontrolled growth. They retain reproduction , often excessively, and responsiveness to some signals, not both . Loss of differentiation, a hallmark of cancer per pathology, makes 'a' correct.