The primary role of the axis in prenatal development is to provide structural support and establish the organization of the developing embryo. The body axis is crucial for determining the spatial arrangement of tissues and organs, guiding the process of morphogenesis. During early development, signals from the axis inform cells where they should migrate and how they should differentiate. This process is fundamental for the proper formation of body symmetry and organ placement. Therefore, the axis is integral to achieving a correctly functioning organism at birth.