What is the last step in embryogenesis?

The last step in embryogenesis is neurulation. This process follows the earlier stages of development, including fertilization, cleavage, and gastrulation. During neurulation, the neural tube forms from the ectoderm, which later develops into the central nervous system (the brain and spinal cord). This is a critical phase because it establishes the foundational structure of the organism’s nervous system.

While fertilization is the initial step that begins the formation of an embryo, and implantation is the process by which the embryo embeds itself into the uterine wall, these precede neurulation in the developmental timeline. Gastrulation, which is also an earlier process, organizes the embryo into germ layers, setting the stage for neurulation. By the time neurulation occurs, the embryo is already complex and established with layers that will develop into various organs and systems. Thus, neurulation signifies a pivotal and concluding phase in the sequence of events that define embryogenesis, coinciding with the early stages of organogenesis.