Which type of animal maintains a constant internal body temperature?

endotherm

ectotherm

coelomate

mesoderm

endotherm

Explanation:

Endothermic animals raise body temperature and keep it constant from internal mechanisms, that is, the animal's own metabolism can control its temperature. Ectothermal animals are not able to regulate body temperature with internal mechanisms, so they need external heat sources to raise and maintain their constant body temperature. These animals get heat from the environment (outdoors), usually by exposure to the sun or in contact with hot surfaces such as rocks.

Endotherm