Which term describes the external opening used for smelling in reptiles?

Which term describes the external opening used for smelling in reptiles?

• A. Ear
• B. Eye
• C. Nostril / nose
• D. Mouth

Answer: (C)

Smell starts at the nostrils, the external openings that lead into the nasal cavity. Air carrying odor molecules enters through the nostrils (nares), where olfactory receptors detect these chemicals and send signals to the brain. In reptiles, scent can also be sampled by the tongue and delivered to the vomeronasal organ (Jacobson’s organ) for enhanced detection of pheromones, but the physical opening used to perceive smells is the nostril. The other openings—the ear for hearing, the eye for vision, and the mouth for ingestion and taste—do not serve as the primary smell entry points.

Smell starts at the nostrils, the external openings that lead into the nasal cavity. Air carrying odor molecules enters through the nostrils (nares), where olfactory receptors detect these chemicals and send signals to the brain. In reptiles, scent can also be sampled by the tongue and delivered to the vomeronasal organ (Jacobson’s organ) for enhanced detection of pheromones, but the physical opening used to perceive smells is the nostril. The other openings—the ear for hearing, the eye for vision, and the mouth for ingestion and taste—do not serve as the primary smell entry points.