Gastrulas

Gastrulas are embryo stage animals that are formed after the process of gastrulation. During gastrulation, a single-layered blastula, formed through cleavage of the zygote, develops into a multilayered organism. During this process, cells rearrange to form the three germ layers (ectoderm, mesoderm, and endoderm), which will eventually become the adult organs and tissues of an organism. This is a crucial stage of embryonic development in most animals and its importance lies in the fact that it helps to form the basic shape and organization of the different body parts. Gastrulation is thus essential for the development of an embryo into a fully-formed organism, and is the first step towards the formation of complex organs and systems.