• Ectoderm is the outermost layer of the primary germ cells, but the endoderm is the innermost layer of the early embryo.
• Both cell layers line some common as well as separate organs but endoderm never lines any exteriorly exposed organ.
• Few genes are required to form the ectoderm, but most of the genes of the genome are required to form the endoderm.
• The endoderm cells are mostly columnar shaped while there is no particular shape or has almost all the shapes of cells in ectodermic cells after differentiation.