Practice question

Neurulation exemplifies morphogenesis where coordinated cell behaviors generate three-dimensional structures. After gastrulation establishes three germ layers, ectodermal cells overlying notochord thicken into neural plate under BMP inhibition by chordin, noggin, and follistatin. Plate edges elevate via apical constriction mediated by actin-myosin contraction and hinge point formation, then fold and fuse forming neural tube that differentiates into brain and spinal cord. This conversion of flat sheet into tube involves cell shape changes, adhesion shifts, and movement without altering cell type initially. Thus neural plate formation illustrates morphogenetic mechanism central to organ architecture.