Which animal's heart has fewer chambers than a human heart: frog, dog, rooster, monkey? - briefly
The frog's heart has fewer chambers than a human heart. It consists of only three chambers: two atria and one ventricle.
Which animal's heart has fewer chambers than a human heart: frog, dog, rooster, monkey? - in detail
The structure and complexity of an animal's heart are closely tied to its physiological needs and evolutionary adaptations. Humans possess a four-chambered heart, which is highly efficient for maintaining separate oxygenated and deoxygenated blood flows. Among the listed animals—frog, dog, rooster, and monkey—the frog's heart has fewer chambers than that of a human.
Frogs have a three-chambered heart, comprising two atria and one ventricle. This structure is sufficient for their needs due to the low metabolic demands of their cold-blooded physiology. The partial separation of oxygenated and deoxygenated blood in the frog's heart ensures adequate oxygen supply to vital organs while accommodating the lower oxygen requirements typical of ectothermic animals.
In contrast, dogs, roosters, and monkeys all have four-chambered hearts similar to humans. This four-chambered structure is more common among warm-blooded (endothermic) vertebrates, reflecting the higher metabolic rates and oxygen demands of these animals. The complete separation of blood flows in a four-chambered heart allows for more efficient oxygen delivery and waste removal, which is crucial for maintaining the elevated body temperatures and sustained activity levels characteristic of endotherms.
Therefore, among the listed animals, it is the frog whose heart has fewer chambers than that of a human. This difference underscores the diverse adaptations in cardiac structure that have evolved to meet the specific physiological requirements of different species.