Organ Detecting Pheromones
Pheromones are detected by:
- Vomeronasal organ only
- Jacobson organ only
- Meckel's diverticulum
- Both Vomeronasal organ and Jacobson organ — Correct Answer
Correct Answer: Both Vomeronasal organ and Jacobson organ
Pheromones are detected by the Vomeronasal organ (VNO) — which is the same structure also known as the organ of Jacobson. Both names refer to the same anatomical structure, so both options (a and c) are correct.
Vomeronasal Organ (VNO) / Organ of Jacobson
- A chemosensory organ located in the nasal cavity (or roof of mouth in some species)
- Contains sensory neurons that detect non-volatile chemical signals (pheromones)
- Sends signals directly to the brain's limbic system (especially the hypothalamus) — bypassing the olfactory bulb
- Responsible for triggering reproductive and social behavioral responses
Flehmen Response
Many animals (horses, cattle, cats, lions) display the Flehmen response — curling the upper lip and inhaling through the mouth — to draw pheromones more effectively into the VNO. This is commonly seen when males detect female pheromones during estrus.
Why Meckel's Diverticulum Is Wrong
Meckel's diverticulum is a remnant of the omphalomesenteric duct (yolk sac) in the small intestine — a completely different structure with no role in pheromone detection.
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
