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.
1. Eiffel Tower â Paris, France. Constructed in 1889, the Eiffel Tower is one of the most famous structures in the world. Itâs named after the engineer Gustave Eiffel and it was build as the entrance arch for the World Expo of 1889. The tower is 324 meters high, approximately as an 81 storey building.