During cleavage, the mass of cells:
increases
decreases
doubles with every cell division
does not change significantly

does not change significantly

Explanation:

Cleavage is one of the early stages of embryonic development. It consists of the first mitotic divisions, which occur without increasing the volume and mass of the cell. Thus, the first mitotic divisions are atypical, since there is no cytoplasmic recovery and, thus, there is no increase in the total volume of the embryo.

When cleavage occurs, the cell mass does not increase, does not shrink, nor doubles in size; in fact, the cell mass does not undergo any significant changes.