Mammalian pinna is supported by

Correct Answer: A

Rationale: The pinna (external ear) in mammals is supported by elastic cartilage, which provides flexibility and resilience to maintain its shape. Hyaline cartilage is rigid (e.g., nose), white fibrous tissue is dense (e.g., tendons), and calcified cartilage is hardened—elastic cartilage is uniquely suited for the pinna.

Correct Answer: C

Rationale: Carpals (wrist bones) are short bones, cuboidal in shape, providing stability and limited movement. The femur and radius are long bones, and the cranium comprises flat and irregular bones, not short ones.

Correct Answer: A

Rationale: The brain resides in the cranial cavity, a well-defined space within the skull formed by the cranial bones. 'Hole' and 'pit' are vague and not standard terms for this structure.

Correct Answer: B

Rationale: Vertebrae increase in size from top (cervical) to bottom (lumbar) to support greater body weight and stress. Cervical vertebrae are smallest, thoracic intermediate, and lumbar largest, reflecting their load-bearing roles.

Correct Answer: B

Rationale: Ribs 11 and 12 are 'floating ribs,' lacking any attachment to the sternum, unlike false ribs (8–10), which connect indirectly via cartilage. 'Loose' is not a standard term here.