The Cell Cycle and Mitosis
By: Siri Ott and Kira Matthias
Three Reasons Why Mitosis Happens
It happens when damage needs to be reapaired, like if you fall and scrape your knee, mitosis helps the wound heal and scab. Another reason why mitosis happens is when cells in your body die, they need to be replaced. Lastly, your body needs to grow and develop and mitosis helps it do that.
Interphase
In interphase, cells grow, preform their assigned tasks, and make DNA. Cells are in interphase about 90% of the time. Centrioles are a part of cells that move to the outskirts of the cell to get ready for the process of mitosis. They also connect to the chromosomes, which are in the nucleus. This will come on later in the mitosis process. This is the process that prepares cells for mitosis.
Mitosis
Mitosis is the process of dividing DNA and generating new cells. Cells are in this process 10% of the time.
Prophase
Prophase is the very first step in mitosis. In this process, paired chromosomes become visible and the nucleus starts to disappear. Also spindle fibers start to form in the centrioles, and get ready to connect to the centromere. The centromere is what holds two chromosomes together.
Metaphase
Metaphase is the second step of mitosis. In metaphase, paired chromosomes align in the center of the cell. Spindle fibers start to separate the chromosomes, by connecting to the centromere. Also during this process, the centrioles spin away from the chromosomes, the allow the spindle fibers to move.
Anaphase
Anaphase is the third step of mitosis. Anaphase is very similar to Metaphase. The only difference is that the chromosomes fully split. This happens because the spindle fibers wind back up in the centrioles while still connected to the chromosomes.
Telophase
The last step in mitosis is Telophase. In the process of telophase two nuclei start to form in the cell. Spindle fibers begin to disappear completely, chromosomes become separate cells, and cytoplasm begins to divide to create a new cell.
Cytokinesis
Cytokinesis is the process of cell division. In cell division, one cell becomes two cells, and the cytoplasm completely divides to create two nuclei. Chromosomes also start to disappear, and centrioles come together at the top of the cell. Cytokinesis needs the process of mitosis and meiosis.