Question

Four chambered heart is found in
(a) Cobra
(b) Tortoise
(c) Salamander
(d) Crocodile

Answer 1

Hint: The animals in class reptilia have 3 chambered hearts but there are some exceptions in reptiles that bear 4 chambers in their hearts.

Complete answer:
The reptile heart is three-chambered. It consists of a left auricle and a right auricle. In three chambered hearts of turtles, snakes, and lizards, an incomplete septum partially divides the single ventricle into separate chambers.
But in alligators and crocodiles, the ventricles are completely divided. These are the exceptions in the class reptilia. And thus crocodiles and alligators have 4 chambered hearts.

Additional information:
-Only the SA node is present in the right auricle of reptiles and no other nodes are present.
-Some vertebrates with double circulation are intermittent breathers.
-The red blood corpuscles in reptiles are oval and nucleated and the reptiles are cold-blooded.
- In reptiles, two major arteries, called aortas, are present that lead to the systemic circulation. There is one sinus venosus and conus arteriosus.
-Four chambered hearts is an avian and mammalian feature.

So, the correct answer is ‘crocodile’.

Note:
-Birds and mammals have four-chambered hearts. The ventricles are divided completely by the septum.
-Birds and mammals cannot vary the blood flow to the lungs without varying blood flow throughout the body in parallel, Unlike the amphibians and the reptiles which can easily do so.
-T.H. Huxley said, “Birds are glorified reptiles.”