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. The Eiffel Tower is the tallest building in France composed of massive latticework structure. The Eiffel Tower is currently owned by the City of Paris and is used as a landmark for visitors. The Eiffel Tower was built for the Paris Exposition of 1889. The Eiffel tower was finished in 1889 and was nearly torn down 20 years later after its lease expired. However, it was kept because many thought its antenna for telegraphy would be useful. In 1910, it became part of the International Time Service.