gastrula
/ˈɡæstrələ/
noun
- An early stage in the development of an animal embryo, consisting of a cup-shaped structure with two layers of cells.
- In a gastrula, the outer layer is called the ectoderm and the inner layer is the endoderm.
- The scientist observed the frog embryo as it changed from a blastula into a gastrula.
- During the gastrula stage, the embryo begins to form distinct cell layers that will become different organs.