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 Blog Entries
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 Dividing Cells Q2 Interphase is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. Prophase: During this first mitotic stage, the nucleolus fades and condenses into chromosomes. Each chromosome comprises two chromatids.Microtubules of the cytoskeleton disassemble. In the Prometaphase stage the nuclear envelope breaks down and there is no longer a nucleous. Some mitotic spindle fibers elongate from the centrosomes and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center. Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles. Telophase: The daughter chromosomes arrive at the poles and the spindle fibers disappear. Cytokinesis: The spindle fibers begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase. Difference between mitosis and meiosis: Mitosis splits apart to become two different cells. Meiosis is a lot like making babies. It comes together instead of spliiting and in the last phase it creates 2 babies then in the metaphase it creates 4 daughter cells. Article posted January 24, 2012 at 12:25 PM • comment • Reads 767 • see all articles |
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