Final answer:
Animals that can regulate their body temperature independently of the environment are known as endotherms, which maintain a constant body temperature through internal mechanisms.
Step-by-step explanation:
Animals that regulate their body temperature independently of the environment are called endotherms. These organisms possess internal mechanisms that allow them to maintain a relatively constant body temperature, regardless of external environmental temperatures.
Endothermy is a characteristic of animals like mammals and birds which evolved from reptile-like ancestors. By regulating their body temperature internally, endotherms can sustain high metabolic rates and keep their cells functioning efficiently under cold conditions, unlike ectotherms whose body temperatures and metabolic rates are influenced by their surroundings.