Organisms must stay at a constant body temperature to live. To control body temperature, organisms need a source of heat, a way to conserve it, and a way to get rid of extra heat. Different organisms have different ways to control body temperature.
⦁ ____________ use their environment as their source of heat and cooling.
⦁ ____________ make most of the heat they need as a by-product of metabolic activity.
⦁ Ectotherms use their environment as their source of heat and cooling.
⦁ Endotherms make most of the heat they need as a by-product of metabolic activity.