what is invagination
- Invagination is the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation the massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layeredorganism, with differentiated germ layers: endoderm, mesoderm, and ectoderm. More localized invaginations also occur later in embryonic development,