This undifferentiated embryonic structure then undergoes a phase of major cell migration called gastrulation, producing a gastrula with three separate germ layers: the endoderm, mesoderm, and ectoderm. Endoderm The endoderm is formed from cells that migrate toward the center of the developing gastrula.
The Eiffel tower is made of puddled iron. It is made up of steel in steel X's. The Eiffel Tower is made of iron. The Eiffel Tower is made of pure iron.
Eiffel Tower. 31 March 1889. The Eiffel Tower is an iron lattice tower located on the Champ de Mars in Paris. It was completed on 31 March 1889 and took two years, two months, and five days to build.