A holoblastic cleavage producing blastomeres of unequal size.
An example is the holoblastic cleavage in a frog egg where a fair amount of yolk concentrates toward the vegetal pole. Because of the concentration of the yolk at the vegetal pole, cleavage results in blastomeres in different size. That is, the blastomeres are smaller in animal pole while larger in vegetal pole.
Compare: equal cleavage
See also: holoblastic cleavage