Which of the following statement is true regarding gastrulation?
Establishes all the three germ layers
Usually occurs at 4 weeks of gestation
Involves the hypoblastic cells of inner cell mass
Occurs at the caudal end of the embryo prior to its cephalic end
Gastrulation is the formation process by which the 3 germ layers and axial skeleton are established in the embryo. It is the beginning of morphogenesis. It occurs during the third week of gestation. 3 germ layers which are formed includes ectoderm, endoderm and mesoderm.Ref: The Developing Human, Keith L. Moore, 7th Edition, Page 60 ; Langman's Medical Embryology, 8th Edition, Page 61