Final answer:
An endotherm is an animal that maintains its body temperature through internal metabolic heat production. These animals have adaptations like fur, fat, feathers, and brown fat to generate and conserve heat, and they can modulate their metabolism to adapt to temperature extremes.
Step-by-step explanation:
An animal that maintains its body temperature by using heat generated from its own metabolism is a endotherm. Endothermic animals, which include mammals and birds, regulate their body temperature internally through metabolic processes. This allows them to maintain high levels of activity and metabolic rates regardless of the external temperature. Endotherms utilize various mechanisms to generate and conserve heat, including muscle contractions that create metabolic waste heat, shivering reflexes to produce warmth, and the use of brown fat that specializes in heat generation.
Insulation in the form of fur, fat, or feathers is critical for endotherms to conserve body heat, enabling them to maintain a stable body temperature. This thermoregulation provides a constant temperature optimal for cellular functions and, while energetically costly, allows endotherms to adapt their metabolism to extreme temperatures through processes like hibernation, aestivation, or migration to manage their internal heat production and conservation.