Two comparisons between frog and human hearts are:
1. **Chamber Configuration:** Both frog and human hearts have four chambers: two atria and two ventricles. However, the arrangement and relative sizes of these chambers differ between the two species.
2. **Blood Flow:** In both frog and human hearts, blood flows through the heart in a double circulatory system. However, the specifics of blood flow, such as the path through the chambers and the valves' functions, differ due to differences in anatomy and physiology between the two species.
