Answer:NOT ALL VERTEBRATES ARE WARM-BLOODED.Warm-blooded vertebrates (endotherms):Birds and mammals. They regulate their own body temperature internally and maintain it regardless of the environment.Cold-blooded vertebrates (ectotherms):Fish, amphibians, and reptiles. Their body temperature changes with the environment since they rely on external heat sources.So, only some vertebrates are warm-blooded, not all.