Question

Which characteristic feature out of the following differentiates birds them from fishes, amphibians and reptiles?

• A. Four chambered heart.
• B. Presence of vertebral column.
• C. Terrestrial life.
• D. Presence of kidneys as excretory organs.

Answer 1

The correct option is A Four chambered heart.

Four chambered heart is one of the most important feature of birds. Although it is seen in crocodile, the four chambered heart becomes a well-defined feature in birds for the first time during evolution. The four chambered heart allows the organisms to keep the oxygenated and deoxygenated blood separate.