Question

Assertion: Calotes, Crococdilus and Chameleons are members of Class Reptilia.
Reason: Heart is three chambered in Calotes, Crococdilus, and Chameleons.
(a)Both assertion and reason are correct and the reason is the correct explanation for the assertion.
(b)Both assertion and reason are correct but the reason is not the correct explanation for us version
(c)Assertion is correct but the reason is incorrect
(d)Both assertion and reason are incorrect

Answer 1

Calotes, Crocodilus, and Chameleonsare members of class Reptilia, and all reptiles have a three-chambered heart with some exceptions.

Complete answer:
Organisms belonging to reptilia generally have two atria and one ventricle. This means they have a three-chambered heart. But this class also has exceptions, such as some 23 living species of crocodilians (alligators, caimans, crocodiles, and gharials) have four-chambered hearts with two atria and two ventricles similar to aves and mammals.
Crocodiles also have a four-chambered heart, which has evolved due to adaptation, as they spend the maximum part of their life cycle in the water. Therefore, they need to reduce the oxygen loss when underwater and it is done by the four-chambered heart by reducing the heartbeats by 2-3/ minute and normalizing this rate when the crocodile comes above water.

Additional information:
All reptiles have a three-chambered heart consisting of two atria and one ventricle, except for crocodiles with a four-chambered heart. The chamber on the right side of the body called the right atrium receives deoxygenated, or “spent,” blood returning from the body tissues. This blood is then passed into the ventricle, from where it is pumped to the lungs for oxygenation. The oxygenated blood returns to the left atrium from the lungs and once again enters the same ventricle, from which it is pumped to the body tissues.

So, the correct answer is option is c.

Notes: The heart rate of reptiles is determined on the basis of species, size, temperature, and activity/level of metabolic function. For this an equation has been employed for metabolic scaling for determination of the "appropriate" heart rate in reptiles has been proposed that is heart rate = 33.4(Weight in kilograms-0.25 ). Additionally, this equation assumes that the reptile species is within its preferred optimal temperature zone.