What is an ectothermic vertebrate?

And so, an endothermic vertebrate is an animal that can produce its own heat and possesses a spinal backbone consisting of vertebrae. Examples of these organisms include most mammals (including humans), most birds, and some reptiles.

Explanation:

Ectothermic vertebrates are, for example, fish, amphibians and reptiles. Their temperature depends on the environment. The contrary to ectothermic are endothermic vertebrates, such as birds or mammals

the core of the sun is so hot and there is so much pressure, nuclear fusion takes place, hydrogen is changed to helium. nuclear fusion creates heat and photons. when the heat reaches the earth it warms the molecules of the atmosphere, and they warm other molecules and so on.