of chromosomes and the alignment of centromeres on the metaphase plate represent essential prerequisites for the orderly separation of the replicated genome into two equal parts. The replicated chromosomes converge toward the center of the spindle, and once they get there, all movements cease. On either side of each centromere are sites for microtubule attachment to the chromosome; electron microscopists called these plate-like structures kinetochores. The kinetochores are not visible with the light microscope. At several points during metaphase, the chromatid arms may unwind from each other. This unwinding is especially apparent late in metaphase, just 1 or 2 minutes before the chromatids will split apart at their centromeres, with each replicated chromosome giving rise to two daughter chromosomes. Anaphase commences with the initial splitting of sister chromatids at their centromeres. These daughter chromosomes then begin to separate from each other, each moving away from the metaphase plate and toward one of the two spindle pole regions. The mechanisms that control chromosome separation clearly involve the interactions between microtubules and components in or near the kinetochore. Sometime after anaphase onset, the chromosomes have moved close to the spindle pole regions, and the spindle middle begins to clear. In this middle region of the spindle, a thin line of vesicles begins to grow. The vesicle aggregation event is a harbinger to the assembly of a new cell wall that will be positioned midway along the length of the original cell. It will form the boundary between the newly separating daughter cells. This basket shaped structure forms in late anaphase or early telophase and breaksdown about the time that the vesicles begin to grow.In Meiosis and Meitosis we deal with many of the same stages that it takes to create a new life form. Cell Division in meiosis and meitosis are very similar in that they can create and vary cell form...
