Accommodations must be made. The one cell Xenopus embryo (left) is over 1 mm across, while cells within the embryo several hours later (right) are closer to 50 microns. Mitotic spindles are shown in red and chromosomes in yellow. Complex mechanisms have evolved to allow for cellular functions such as cytokinesis and mitosis to be effective in cells of diverse sizes. Images are courtesy of Martin Wühr (Harvard).