14.Which layer of embryo is formed first? A. Ectoderm B. Mesoderm C. Endoderm D. Both b&c
option c. The endoderm is one of the germ layers shaped for the duration of animal embryogenesis. Cells migrating inward alongside the archenteron shape the internal layer of the gastrula, which develops into the endoderm. It is the primary layer to be developed.
