CBSE Class 10 Answered

Amphibians and reptiles have 3-chambered heart whereas birds and mammals have 4-chambered heart.

The 4 chambered heart differs from the 3 chambered heart in that it keeps oxygenated blood completely separate from de-oxygnated blood, because there is one ventricle for deoxgynated blood and one for oxygenated blood. In the 3 chambered heart, a single ventricle pumps both out of the heart, and there is some mixing between fresh and old blood. The 2 ventricle-4 chamber heart prevents mixing, thereby allowing the blood leaving the heart to have far more oxygen than it would otherwise. This is good for enhancing the more fast paced lifestyle that birds and mammals tend to have, giving an advantage to having a 4 chambered heart. In addition, birds and mammals are endothermic and require greater energy to maintain their body temperatures. This is possible due to their 4-chambered heart.