2007/07/23

Meiosis II

Prophase II: Takes an inversely proportional time compared to telophase I. In this prophase we see the disappearance of the nucleoli and the nuclear envelope again as well as the shortening and thickening of the chromatids. Centrioles move to the polar regions and are arranged by spindle fibres. The new equatorial plane is rotated by 90 degrees when compared to meiosis I, perpendicular to the previous plane.
Metaphase II: The centromeres contain three kinetochores, organizing fibers from the centrosomes on each side.
Anaphase II: Where the centromeres are cleaved, allowing the kinetochores to pull the sister chromatids apart. The sister chromatids by convention are now called sister chromosomes, and they are pulled toward opposing poles.
Telophase II: Which is similar to telophase I, marked by uncoiling, lengthening, and disappearance of the chromosomes occur as the disappearance of the microtubules. Nuclear envelopes reform; cleavage or cell wall formation eventually produces a total of four daughter cells, each with a haploid set of chromosomes. Meiosis is now complete.

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