Describe a significance event that occurs in each of the four stages of mitosis?

Answer 1

In prophase, the genetic material in the nucleus is in a loosely bundled coil (chromatin). The Chromatin condense together into a highly ordered structure called a chromosome. Since the genetic material has already been duplicated, the replicated chromosomes have two sister chromatids, bound together at the centromere.

In metaphase, microtubules find and attach to the centromeres of the chromosomes, and pull the chromosomes where they convene along the metaphase plate (middle of the cell).

In anaphase, the sister chromatids are cleaved, allowing them to separate into distinct sister chromosomes, and are pulled apart by shortening the microtubules. This causes the chromosomes tom move toward the respective ends of the cell to which they are attached.

Finally, in telophase microtubules continue to lengthen, elongating the cell even more. Corresponding sister chromosomes attach at opposite ends of the cell. A new nuclear envelope forms around each set of separated sister chromosomes. Both sets of chromosomes, now surrounded by new nuclei, unfold back into chromatin. Cytokinesis also occurs in which the cell breaks (furrows) into two distinct cells.

Answer 2

In prophase, the nuclear envelope breaks down and the chromatin condenses into chromosomes. In metaphase, the chromosomes align along the metaphase plate. In anaphase, the sister chromatids are pulled apart and move towards opposite poles. In telophase, the nuclear envelope reforms around the separated chromosomes.