How many chambers are there in the heart of a frog?

The heart of a frog contains three chambers: two atria and one ventricle. This structure is adapted to the amphibious nature of frogs, as it allows for a combination of oxygenated and deoxygenated blood to be mixed. The upper two chambers, the atria, receive blood from the body and lungs, while the single ventricle pumps the mixed blood to the rest of the body. This unique arrangement supports their lifestyle, which includes both aquatic and terrestrial phases. Thus, the option indicating three chambers is the correct answer in the context of frog anatomy.