So as our two centrioles move apart to opposite ends of the cell to opposite poles of the cell our microtubules, the spindle fibers, also known as asters, begin to grow and they radiate outward towards the center of our cell, towards our nucleus. At the same time that happens our nuclear membrane begins to deteriorate and the nucleolus disappears altogether. And what this basically does is it allows the spindle fibers to make its way into the nucleus region of our cell so that our spindle fibers, as we'll see in just a moment can actually attach to a special region on the centromere. So basically, each one of these chromosomes are connected by a centromere or the region where they connect is called the centromere. And what also happens in ProPhase is the centromeres of the chromosomes develop these attachment points known as kinetochores. So this concludes ProPhase.