Question

Which of the following has 4 chambered heart:

• A. aves
• B. mammals
• C. crocodiles
• D. all

Answer 1

The correct option is D

all

Birds and mammals have 4 chambered heart, and crocodiles are the one reptilian exception, that has 4 chambers (2 atria, 2 ventricles).
Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left.