The process of forming three germ layers from the embryonic disk is called ________.

A) gastrulation
B) differentiation
C) fertilization
D) meiosis
E) implantation

Gastrulation

During the early stages of embryonic evolution in a wide range of animals, the simple, single-layered structure called a blastula rearranges itself into a complex, multilayered formation known as the gastrula.

Embryonic Disk

A key structure in early embryonic development, from which the embryo begins to form and differentiate into various tissues and organ systems.

Germ Layers

The three primary layers of cells (endoderm, mesoderm, and ectoderm) in an embryo from which all tissues and organs develop.