Question #64
What is the process of gastrulation?
Gastrulation is the process by which cells of the epiblast migrate and specialise to form the three germ layers (the ectoderm, mesoderm and endoderm).
As the cells migrate and change shape a ridge appears on the surface. This is known as the primitive streak.
At one end of the primitive streak there are so many cells migrating and moving to form the mesoderm layer, a pit forms. This is known as the primitive node and it marks the cranial end of the embryo.