cleavage /klē″vij/ [AS, cleofan, to split] , 1. the series of repeated mitotic cell divisions that occur in an ovum immediately after fertilization. It transforms the single-celled zygote into a multicellular embryo capable of growth and differentiation. During cleavage, the embryo remains uniform in size as its cells, or blastomeres, become smaller with each division. Kinds include determinate cleavage, equal cleavage, indeterminate cleavage, partial cleavage, total cleavage, unequal cleavage. 2. the act or process of splitting, primarily a complex molecule into two or more simpler molecules. −cleave, v.
