Before the cell divides, the DNA is replicated and packaged in the form of chromosomes. During division, each new daughter cell receives one complete set of chromosomes, providing each cell with the complete genetic information necessary for life and for continued cell replication. Oddly enough, no one really knows how the cell manages this feat of near-total reorganization. Biologists do know that in order for one cell to become two, a number of exquisitely timed changes must take place. The nuclear membrane must be broken down and the replicated chromosomes must be brought into line.
Most cells have one centrosome, which is replicated shortly before cell division.
During division, the two centrosomes migrate to opposite sides of the nucleus. Lovely, star-shaped asters form around the wandering centrosomes, and then a spindle appears spanning the space between the two centrosomes. But the hundreds of other proteins in the centrosome are still unknown. And the process of centrosome replication remains a mystery. Getting the centrosome out of the cell These basic questions about centrosomes have remained unanswered in large part because no one has been able to isolate the structures and to get them working outside of the cell.