Which term describes an animal that maintains a constant body temperature independent of the environment?

• A. Endothermy
• B. Ectothermy
• C. Homeostasis
• D. Metamorphosis

Answer: (A)

Endothermy describes animals that maintain a relatively constant internal body temperature regardless of environmental changes. This stability comes from producing heat metabolically and using insulation or cooling mechanisms as needed, so the organism stays warm in cold surroundings or avoids overheating in hot ones. Mammals and birds are common examples of endotherms because they keep their body temperature steady even when the outside temperature shifts.

Ectothermy, by contrast, refers to animals whose body temperature largely follows the environment; they rely more on external heat sources to regulate warmth, so their body temperature changes with conditions. Homeostasis is the broader idea of keeping internal conditions stable, which includes temperature but also other factors like pH and glucose levels. Metamorphosis is a developmental change, not related to how an animal regulates temperature.