The chromosomes are then pulled apart by the spindle fibers, resulting in two new daughter cells. This process begins with the formation of the spindle fibers, which then attach to the chromosomes. Prophase I is the first stage of mitosis, and it is responsible for the separation of sister chromatids. The prophase I phase takes up 1/4 of the total time that it takes for an individual cell to complete its entire cycle of mitosis. Prophase I occurs before the metaphase plate forms- this plate separates sister chromatids during metaphase ii to create new daughter cells after cytokinesis has occurred. These events are necessary to make way for later stages in mitosis. This process includes two main events: Chromatin condensation and nuclear envelope breakdown. Prophase i is the first stage of mitosis, which is a type of cell division. N prophase II, there are two new nuclei formed in each cell In prophase I, the nuclear membrane breaks down In propointe II there are two copies per chromosome – one copy from each pair of sister chromatids that was present during meiosis 1
In prophase I, each chromosome has 4 pairs of sister chromatids (two copies per chromosome Prophase II is the second stage of meiosis, and it is also called zygotene Prophase I is the first stage of meiosis, and it is also called the leptotene phase Prophase II is when the chromosomes have replicated themselves and they become visible to a microscope In prophase I, the chromosomes have not yet replicated themselves Prophase ii includes metaphase and anaphase Prophase i is the first phase of mitosis, which is when the nuclear envelope breaks down. Comparison between Prophase I and Prophase ii Parameters of Comparison We will now move onto metaphase I where sister chromatids are pulled towards opposite poles – this process is called spindle formation or bipolarity.
Thus far we have seen four stages: interkinesis (a resting period), prophase 1-4 (nuclear division). Prophase ii also marks the final stage in the nuclear division before mitosis. The result is that each chromosome has been duplicated to create two identical sets. In prophase ii, which occurs after DNA synthesis has occurred and before metaphase I, the cell becomes divided into two cells by a cleavage furrow. In the first phase of meiosis, prophase I, an individual’s chromosomes condense and become visible. Whereas during prophase II, this has already occurred so no part of the cell moves or changes shape before metaphase begins. This process continues until all four pairs have been separated due to forces exerted by microtubules. The second major difference is that during the first phase of mitosis, spindle fibers form a network around each pair of sister chromatids to pull them apart from one another. In Prophase II, they become long thin rods (called telophase). The first major difference between prophase I and prophase II is that in Prophase I, the chromosomes are condensed into visible threads called chromatids. Last Updated on Maby QCity Editorial Stuff
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