Which of the following groups of animals is known to be endothermic?

The group of animals known to be endothermic includes mammals and birds. Endothermic animals, also referred to as warm-blooded animals, have the ability to regulate their body temperature internally. This physiological characteristic allows them to maintain a stable internal environment, which is crucial for their survival, especially in varying external conditions.

Mammals possess fur or hair and have specialized mechanisms such as sweating and shivering to help regulate their body heat. Birds, on the other hand, have feathers and also utilize various behaviors and metabolic processes to keep warm. Both groups maintain a higher body temperature than their surrounding environment, allowing them to be active in a range of temperatures and conditions.

In contrast, the other groups mentioned, such as reptiles, amphibians, fish, insects, arthropods, and cephalopods, are typically ectothermic, meaning their body temperature depends largely on external environmental temperatures. This difference fundamentally affects their behavior, activity levels, and habitats.