Organisms belonging to which of the following classes have a four-chambered heart?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. Class Aves.
Organisms belonging to Class Aves, which are birds, possess a four-chambered heart. This highly efficient circulatory system, with two atria and two ventricles, ensures complete separation of oxygenated and deoxygenated blood. This complete separation is crucial for birds, as their high metabolic rate (necessary for flight and maintaining body temperature) demands a constant and efficient supply of oxygen to their tissues.