cleavage
noun(cleav-age)
the quality of a crystallized substance or rock of splitting along definite planes; also : the occurrence of such splitting
cleavage
noun(cleav-age)
a fragment (as of a diamond) obtained by splitting
cleavage
noun(cleav-age)
the action of cleaving or splitting : the state of being cleft
cleavage
noun(cleav-age)
meroblastic cleavage in which a disk of cells is produced at the animal pole of the zygote (as in bird eggs)
cleavage
noun(cleav-age)
holoblastic cleavage that is typical of deuterostomes and that is characterized by arrangement of the blastomeres of each upper tier directly over those of the next lower tier resulting in radial symmetry around the pole to pole axis of the embryo
cleavage
noun(cleav-age)
holoblastic cleavage that is typical of protostomes and that is characterized by arrangement of the blastomeres of each upper tier over the cell junctions of the next lower tier so that the blastomeres spiral around the pole to pole axis of the embryo