The reptile's body temperature rises when the external temperature rises. When the temperature drops, so does his body temperature. If a reptile feels cold because the external temperatures have made his blood cold, he'll lie in the sun to warm up.
A single undifferentiated cell. For example, in human, this was the embryo.
They go like chains in sides but they are attached to a the main chain.
They have one starting point"Main Chain"and ends in many endings.
Africa is the most likely where most hominids originated from.
