Which of the following classes of animals has/have three-chambered heart?

Vertebrate hearts exhibit varying complexity based on their evolutionary lineage and metabolic needs. Fishes (Pisces) possess a two-chambered heart consisting of one atrium and one ventricle, where blood flows in a single circuit through the gills [1]. Amphibians typically possess a three-chambered heart with two atria and a single ventricle, allowing for double circulation through the lungs/skin and the rest of the body. Most reptiles also share this three-chambered heart structure, featuring a partially divided ventricle that reduces the mixing of oxygenated and deoxygenated blood [1]. While crocodilians are a notable exception within the class Reptilia, possessing a four-chambered heart, the general classification for both amphibians and reptiles is the three-chambered heart [1]. Therefore, the classes that have three-chambered hearts are Amphibia and Reptilia.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > Oxygen enters the blood in the lungs > p. 92