Which process establishes the three definitive germ layers?: (A) Neurulation, (B) Gastrulation, (C) Craniocaudal folding, (D) Lateral folding
Answer is B. Gastrulation - three primary germ layers from epiblast during week 3 of development i.e dorsal ectoderm, middle mesoderm, ventral endoderm. Neurulation is the process by which neuroectoderm forms the neural plate, which eventually folds to form the neural tube.