The correct option is 2: Spiral and determinate cleavage and schizocoele Protostomes represent one of the two major clades of bilaterian animals (the other being Deuterostomes), and they are fundamentally defined by a specific suite of developmental characteristics. The correct set of traits for a protostome embryo includes spiral cleavage, which is an oblique or diagonal pattern of cell division that results in smaller cells lying in the grooves between…Read More