Gastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells), or in...

the three primary germ layers, ectoderm, mesoderm and endoderm, during gastrulation. The amniotic ectoderm and extraembryonic mesoderm also originate from...

continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that...

primitive streak establishes bilateral symmetry, determines the site of gastrulation, and initiates germ layer formation. To form the primitive streak, mesenchymal...

development of the embryo. Cell movements during amphibian gastrulation In frog embryos, gastrulation initiates at the site identified as the gray crescent...

of an organism happens through fertilization, cleavage, blastulation, gastrulation, organogenesis, and metamorphosis into an adult. Each species of animal...

Meckel's diverticulum. In the third week, gastrulation begins with the formation of the primitive streak. Gastrulation occurs when pluripotent stem cells differentiate...

mesoderm is the middle layer of the three germ layers that develops during gastrulation in the very early development of the embryo of most animals. The outer...

implants in the uterus. Embryogenesis continues with the next stage of gastrulation, when the three germ layers of the embryo form in a process called histogenesis...

internal cavity of the primitive gastrointestinal tract that forms during gastrulation in a developing animal embryo. It develops into the endoderm and mesoderm...