Development is the process by which an organism develops from a zygote to its full 3D structure. This journey starts from a single cell to a complex multicellular organism, which does not end at birth. It continues with childhood, puberty and through to early adulthood. All embryos have the same conserved embryonic developmental plan (CEDP), due to which all embryos look the same. Some key mechanisms involved in these developmental phases are growth, differentiation, morphogenesis, gastrulation, and neurulation.
In development, signaling of a vast array of different proteins, by different groups of cells, allow cells to gain information about migration, proliferation, differentiation or something else. Organisation of these cells determine their roles and positions, so whether they form the cranial (head) or caudal (tail) end. Morphogenesis is the formation of shape and movement and manipulation of these cells to assemble tissues and organs. Progressively, cells are guided through migration by attractive and repulsive cues; similar cues also help define tissue boundaries. Therefore, exposing cells to different concentrations of morphogen can change their outcome e.g. cell type; digit formation- a simple structure has become more complex (Webster and de Wreede, 2016).