The Abbasid Caliphate differed from others in that it did not have the same borders and extent as Islam. Particularly, in the west of the Caliphate, there were multiple smaller caliphates that existed in relative peace with them.
The major difference between the protist and the animal kingdom is protists are unicellular protozoans and unicellular & multicellular, but animals are multicellular animals.
The initial difference between the Neolithic and Paleolithic would be the way of living. The Paleolithic age was characterized by hunting basically. Their weapons too were made of wood and bones. The Neolithic were experts in building houses with mud and stone.