What could be the possible explanation for the evolution of four-chambered heart in mammals as opposed to two-chambered heart in fishes?
What could be the possible explanation for the evolution of four-chambered heart in mammals as opposed to two-chambered heart in fishes?
The correct options are
A Fishes do not require energy to maintain body’s temperature.
C Fishes do not have complex body structure like mammals.
In Fishes and Reptiles, the heart is two-chambered and there is mixing of oxygenated and deoxygenated blood. But higher up the ladder, in birds and mammals, the heart has four chambers and oxygenated blood and deoxygenated blood is kept strictly separated. The possible explanation for this evolution is that fishes and reptiles are cold-blooded (the body temperature varies according to the surrounding temperature). So energy is required only for locomotion and hence less amount of oxygen is sufficient. Birds and mammals are warm-blooded, so more energy is required to keep up the body temperature. To maintain high energy requirements of the body, more oxygen supply is required and therefore oxygenated and deoxygenated blood cannot be mixed.
Also, complexities in the body structure and different mechanisms have increased with evolution. Therefore the mechanism of circulation has also evolved.
A
Fishes do not require energy to maintain body’s temperature.
C
Fishes do not have complex body structure like mammals.
In Fishes and Reptiles, the heart is two-chambered and there is mixing of oxygenated and deoxygenated blood. But higher up the ladder, in birds and mammals, the heart has four chambers and oxygenated blood and deoxygenated blood is kept strictly separated. The possible explanation for this evolution is that fishes and reptiles are cold-blooded (the body temperature varies according to the surrounding temperature). So energy is required only for locomotion and hence less amount of oxygen is sufficient. Birds and mammals are warm-blooded, so more energy is required to keep up the body temperature. To maintain high energy requirements of the body, more oxygen supply is required and therefore oxygenated and deoxygenated blood cannot be mixed.
Also, complexities in the body structure and different mechanisms have increased with evolution. Therefore the mechanism of circulation has also evolved.
