The outermost germ layer is known as what?

The outermost germ layer in the developing embryo is known as the ectoderm. This layer is responsible for forming structures that are critical in the development of the organism, such as the skin, hair, nails, and the entire nervous system, including the brain and spinal cord.

The process of gastrulation leads to the formation of the three primary germ layers: ectoderm, mesoderm, and endoderm. While the mesoderm and endoderm form other vital systems and structures, it is the ectoderm that gives rise to the outermost tissues of the body. This layer plays a significant role in establishing the organism's initial body plan during early embryonic development, making it crucial for understanding developmental biology.