How to tell the difference between a GameObject created from FBX directly and one from a prefab?

Because in inpector they all share the very same components and attributes as they are originated from a same fbx mesh.But how should I do if want to detect via scripts which objects are created directly by dragging the fbx into the scene and which are by prefabs.I seems all GameObject models share a same class name "GameObject",not like in MAXScript there are many differecnt classes for mesh objects.

 

Not tested with fbx imports specifically, but from the docs it looks like it should work. I don't know how to do it at runtime.
http://docs.unity3d.com/ScriptReference/PrefabType.html

 

Thank you garth,yes that's how the engine differentiate them.I figured it out earlier,forgot to update here.And the page your direct gives more specifics,thanks a lot.