Question Detail
Question
Avian respiratory system is characterised by the presence of membranous air-sacs. Such structure is also observed as a part of respiratory system in some non-avian vertebrates. Which one of the following possesses such air-sacs?
Correct Answer
Option D is the correct answer.
Detailed Explanation
Air sacs are a distinctive feature of the avian respiratory system, but they are also found in some other vertebrates. Pteropus (flying fox, a bat) is a mammal that has a well-developed system of air sacs that are extensions of the lungs, which may aid in flight by reducing weight and assisting in ventilation. Dolphins are marine mammals with no air sacs; toads have simple lungs; chamaeleon has typical reptilian lungs.
Hint
This flying mammal also possesses air sacs that extend from the lungs and are associated with flight.