Radial cleavage - Metazoa
Radial cleavage produces tiers or layers of cells one on top of another. Radial cleavage is also said to be indeterminate or regulative because each of the blastomeres of the early embryo, if separated from the other, can regulate its development and form a complete well proportioned embryo. This happens because the blastomeres are equipotent; their final fate is not yet determined and there is no definite relation between the position of early blastomeres and specific tissue it will form in the embryo (hence indeterminate). This type of cleavage is found in some cnidarianes, echinoderms and all chordates.
Figure: Radial cleavage shown at 4, 8 and 16 cell stage