The Germ layers consist of about three layers of cells: Ectoderm – exterior germ layer Mesoderm – middle germ layer Endoderm – internal germ layer These three distinct layers are formed after a blastocyst’s inner cell mass undergoes a process of specific organization called gastrulation,[1] which occurs after the blastocyst phase in embryonic development. Organization or Gastrulation [2] involves many things including distinct differentiation patterns …