ANATOMY

Detailed explanation-1: -(a) Double circulation is characteristic of all vertebrates. (b) Blood volume in pulmonary circulation is higher than the volume of blood in systemic circulation at any instant. (c) A double aortic arch can be seen in birds and mammals.

Detailed explanation-2: -Double circulation is the sort of circulation where blood goes to the heart twice. It is fundamentally found in birds, warm blooded animals, and a few reptiles and fishes. Hence, out of the alternatives given in the question, alligator, lungfish, crocodile, birds, and mammals have double circulation.

Detailed explanation-3: -Assertion : human heart shows double circulation . Reason : In double circulation the oxygenated and deoxygenated, blood are mixed and pass through the heart only once .

Detailed explanation-4: -Double circulation supports a strict separation of both oxygenated and deoxygenated blood. Therefore, this circulation ensures that the body always has a dedicated supply of oxygen and also, it improves body efficiency. This is also one of the reasons why mammals can maintain their body temperatures.

Detailed explanation-5: -Answer: The incorrect statement is (b); it occurs in all vertebrates. Explanation: When blood circulates twice through the heart during an one complete cycle, it is known as Double circulation. It is found in frogs, reptiles, birds, and mammals not in all vertebrates.