Studying the Embryonic Cell Cluster (ECC):Early in the development of the embryo, there is a point where there are just 8 cells. This is the last point where all the cells are the same. This is the last point in development before cells begin to differentiate. After this point, the cells that develop have specific functions. Some turn into skin cells, others turn into organ cells, etc. What cells they become is determined by their location in the embryo. That way we end up with all the pieces and parts in their right places.