How does the frog's heart make its circulatory system less effIncident than the circulatory system?

The frog's heart has three chambers—two atria and one ventricle—leading to some mixing of oxygenated and deoxygenated blood. This design is less efficient than a four-chambered heart, as seen in mammals, because it can result in lower oxygen levels being delivered to the body. Additionally, the single ventricle complicates the separation of pulmonary and systemic circulation, which can reduce overall oxygen delivery efficiency during activity. Consequently, frogs have a less effective circulatory system compared to those of more evolved vertebrates.