Which term describes animals whose body temperature varies with the environment?

• A. Endothermic
• B. Energy
• C. Ectothermic
• D. Food

Answer: (C)

Animals whose body temperature varies with the environment are ectothermic. They rely largely on external heat sources, so their internal temperature follows the ambient conditions, with behavior like basking or seeking shade helping to regulate heat. The opposite term is endothermic, describing animals that generate heat metabolically to keep a relatively constant internal temperature, regardless of surroundings. The other two options don’t relate to temperature regulation.