Question

Assertion: Mammals and birds are warm blooded organisms which maintain a uniform internal body temperature.
Reason: Mammals and birds have a four-chambered heart.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not a correct explanation of A.
• C. A is true but R is false.
• D. A and R are false.

Answer 1

The correct option is A Both A and R are true and R is the correct explanation of A.

Mammals and birds have a four-chambered heart which prevents mixing of oxygenated and deoxygenated blood and makes the oxygen supply to the different parts of the body more efficient as compared to fishes or amphibians which have a 2-chambered and 3-chambered heart respectively. This separation allows the mammals and birds to maintain a high rate of energy production which also helps them in maintaining a uniform body temperature irrespective of the surroundings’ temperature, thus classifying them as warm blooded organisms.