The nuclear membrane reforms and the nucleolus returns. 2. the chromosomes condense and thicken and are now seen as separate, distinct structures. 3. the centrioles first begin to move to opposite sides of the cell. 4. cytokinesis occurs. 5. the nucleolus disappears. 6. the pairs of sister chromatids are lined up at the center of the cell. 7. the cell assembles the special structures needed for cell division. 8. the cell increases its size as well as the number of enzymes and cytoplasmic organelles. 9. the chromatids are pulled to opposite sides of the cell. 10. the nuclear membrane begins to break apart allowing the microtubules to reach the pairs of chromatids. 11. a cleavage furrow or a cell plate forms to divide the cytoplasm into two parts. 12. pairs of sister chromatids become attached to the spindle fibers. 13. the cell prepares for division by replicating the chromosomes. a. interphase b. prophase c. telophase d. prophase e. anaphase f. telephase g. metaphase