Which one of the following animals has a four-chambered heart?
2025
Which one of the following animals has a four-chambered heart?
Answer: C. Crocodile — ConceptVertebrate heart chambers are counted as atria plus ventricles. Amphibians generally have two atria and one ventricle; most non-crocodilian reptiles…
- A.
Snake
- B.
Frog
- C.
Crocodile
- D.
Lizard
Show answer & explanation
Correct answer: C
Concept
Vertebrate heart chambers are counted as atria plus ventricles. Amphibians generally have two atria and one ventricle; most non-crocodilian reptiles retain one incompletely divided ventricle. Crocodilians are the reptilian exception with a complete interventricular septum and two ventricles.
Application
A crocodile is a crocodilian. Its two atria and two fully separated ventricles make four chambers.
Contrast
A snake is a non-crocodilian reptile with two atria and a single incompletely divided ventricle.
A frog is an amphibian with two atria and one undivided ventricle.
A lizard is a non-crocodilian reptile with two atria and a single incompletely divided ventricle.
Cross-check
The comparison criterion is complete anatomical septation, not temporary functional pressure separation. Among the offered animals, only the crocodile belongs to the crocodilians. Therefore, the answer is Crocodile.