In a separate experiment, researchers disrupted the block to polyspermy,
generating embryos with 7 to 10 sperm nuclei. At the end of cleavage, these
embryos had the same nucleusto-cytoplasm ratio as the wild-type embryos, but
cleavage ended at the 10 th cell division rather than the 12 th cell division.
What do these results indicate about the timing of the end of cleavage?
