Which of the following reptiles is with four chambers in the heart? A) Calotes B) Crocodile C) King cobra D) Turtle E) Wall lizard
Hint: Heart is a muscular organ divided into a compartment called a chamber. These chambers are present to separate the oxygen-rich blood from deoxygenated blood. Mammals have a four-chambered heart.
Complete step-by-step answer: Reptiles are vertebrate or we can say backbone animals, which belong to the class of Reptilia. They are known for their creeping or crawling mode of locomotion. Mostly the reptiles are terrestrial animals. The body of these animals is covered by dry and cornified skin, epidermal scales. They are cold-blooded animals. They have the three-chambered heart (that is two atria and single ventricles) except the crocodiles. The crocodiles are only the reptile that has a four-chambered heart (two atria and two ventricles) because of the most complicated blood circulation of all vertebrates. They spent most of their time underwater, so this adaptation (four-chambered) helps to a reduced rate of circulation and save oxygen. The circulation rate, in water, is reduced by reducing the heartbeat by 2 or 3 minutes. As soon as they come out of the water, the circulation rate comes to normal and requires more oxygen. Hence the heart has four-chambered to provide a sufficient amount of oxygen. The crocodiles have all other features of reptiles except the heart structure.
Therefore the correct answer is option B. Options A, C, D and E – These animals also belong to the class Reptilia.
Note: The animals belong - the class Osteichthyes and Chondrichthyes have two-chambered heart, whereas the class of Reptilia and Amphibian have a three-chambered heart. The class of Aves and mammals have a four-chambered heart.