Question map
Which one of the following animals has a three-chambered heart?
Explanation
Vertebrate hearts vary in chamber count based on their evolutionary lineage and metabolic needs. Fish, such as Scoliodon (a dogfish shark), possess a two-chambered heart consisting of one atrium and one ventricle [1]. Amphibians and most reptiles have a three-chambered heart with two atria and a single ventricle, which allows for some mixing of oxygenated and deoxygenated blood [1]. Salamanders are amphibians and thus possess this three-chambered structure. In contrast, birds like the pigeon and mammals like human beings have four-chambered hearts [1]. This complete separation of blood streams prevents mixing and provides a highly efficient oxygen supply, which is essential for maintaining the high energy requirements of warm-blooded (endothermic) animals [1]. Therefore, among the given options, only the salamander has a three-chambered heart.
Sources
- [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Oxygen enters the blood in the lungs > p. 92