EVERYDAY SCIENCE

Detailed explanation-1: -The ectoderm is the outer layer of the embryo, which gives rise to the external ectoderm (epidermis, hair, nails) and the neuroectoderm (neural crest and neural tube-brain and spinal cord), along with the lens of the eyes and the inner ear.

Detailed explanation-2: -During gastrulation, a hollow cluster of cells called a blastula reorganizes into two primary germ layers: an inner layer, called endoderm, and an outer layer, called ectoderm.

Detailed explanation-3: -The nervous system develops from the ectoderm following an inductive signal from the mesoderm. The initial mesodermal cells condense to form the notochord, which elongates under the primitive streak along the anterior-posterior axis of the developing embryo.

Detailed explanation-4: -Three primary germ layers Gastrulation is a key phase in embryonic development when pluripotent stem cells differentiate into the three primordial germ layers: ectoderm, mesoderm and endoderm. The ectoderm gives rise to the skin and the nervous system.