Only two weeks after fertilization, the first sign of the formation of the 3 axes of the human body (head/tail, ventral/dorsal, and right/left) begins to appear. At this stage, known as gastrulation, a flat and featureless sheet of…

Only two weeks after fertilization, the first sign of the formation of the 3 axes of the human body (head/tail, ventral/dorsal, and right/left) begins to appear. At this stage, known as gastrulation, a flat and featureless sheet of…