1. Answer: The correct answer is- A body that does not produce much internal heat.
Ectoherms are those animals whose body temperature depends on their surrounding temperature. They do not produce much internal heat. These animals rather absorb heat from their environment in order to regulate their body temperature. They are called cold-blooded animals.
Example- Reptiles, amphibians, fishes, and invertebrates.
Thus, if an animal is an ectotherm, its body does not produce much internal heat.