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Phases of Mitosis

Pearson
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Cell reproduction, or cell division, includes two processes: mitosis, which is nuclear division, and cytokinesis, which is cytoplasmic division. Because DNA is so important to our cells, division of the nucleus is its own process, mitosis, and it is a very precise process to be sure that the DNA is divided equally into the daughter cells. Mitosis includes four phases: prophase, metaphase, anaphase, and telophase. We will look at the high points of each of these. During interphase, the DNA is stretched out in thin strands called chromatin. Imagine the nucleus looking like a bowl of long tangled strands of angel hair pasta. During prophase, the first phase of mitosis, the chromatin condenses into rod-like structures called chromosomes. They're somewhat like short, wide lasagne noodles and are more easily separated. The centrioles begin to move apart and delicate spindle fibers extend from them and attach to each chromosome to direct their movements during the rest of mitosis. The nuclear envelope breaks down during prophase, so the chromosomes can move freely and the nucleolus dismantles as well. The next phase of mitosis is metaphase. Meta means middle and during metaphase the chromosomes align very precisely along the midline of the cell. Anaphase is next. Ana means away and during anaphase the replicated chromosomes separate, the spindle fibers pull the chromosomes apart and one complete set goes to each side of the cell. The final stage of mitosis is telophase. The chromosomes finish migrating to opposite sides of the cell and this state is rather like the reverse of prophase. The nuclear envelope reappears, as does the nucleolus, and the chromosomes relax back into stretched out chromatin strands. Mitosis is a very precise division of the nucleus, but there's more to a cell than its nucleus. We must still divide the rest of the cell, the cytoplasm. Cytoplasmic division is called cytokinesis. It overlaps the latter part of mitosis. Because the goal of mitosis is to get a full set of DNA into each new cell, cytokinesis doesn't start until anaphase, after the chromosomes separate. It concludes at the end of telophase, finally splitting the original cell into two new daughter cells. And these cells begin their lives in interphase and the cell cycle begins all over again. The cell cycle allows for central processes such as growth and development, repair, and basic maintenance that keeps our bodies growing.
Cell reproduction, or cell division, includes two processes: mitosis, which is nuclear division, and cytokinesis, which is cytoplasmic division. Because DNA is so important to our cells, division of the nucleus is its own process, mitosis, and it is a very precise process to be sure that the DNA is divided equally into the daughter cells. Mitosis includes four phases: prophase, metaphase, anaphase, and telophase. We will look at the high points of each of these. During interphase, the DNA is stretched out in thin strands called chromatin. Imagine the nucleus looking like a bowl of long tangled strands of angel hair pasta. During prophase, the first phase of mitosis, the chromatin condenses into rod-like structures called chromosomes. They're somewhat like short, wide lasagne noodles and are more easily separated. The centrioles begin to move apart and delicate spindle fibers extend from them and attach to each chromosome to direct their movements during the rest of mitosis. The nuclear envelope breaks down during prophase, so the chromosomes can move freely and the nucleolus dismantles as well. The next phase of mitosis is metaphase. Meta means middle and during metaphase the chromosomes align very precisely along the midline of the cell. Anaphase is next. Ana means away and during anaphase the replicated chromosomes separate, the spindle fibers pull the chromosomes apart and one complete set goes to each side of the cell. The final stage of mitosis is telophase. The chromosomes finish migrating to opposite sides of the cell and this state is rather like the reverse of prophase. The nuclear envelope reappears, as does the nucleolus, and the chromosomes relax back into stretched out chromatin strands. Mitosis is a very precise division of the nucleus, but there's more to a cell than its nucleus. We must still divide the rest of the cell, the cytoplasm. Cytoplasmic division is called cytokinesis. It overlaps the latter part of mitosis. Because the goal of mitosis is to get a full set of DNA into each new cell, cytokinesis doesn't start until anaphase, after the chromosomes separate. It concludes at the end of telophase, finally splitting the original cell into two new daughter cells. And these cells begin their lives in interphase and the cell cycle begins all over again. The cell cycle allows for central processes such as growth and development, repair, and basic maintenance that keeps our bodies growing.