Lost Cells: The Cell Cycle Of The Human Body

719 Words 3 Pages
Humans are constantly having to replenish lost cells in their bodies. They do this complicated task by a process called mitosis, which is part of the cell cycle, and mitosis allows one cell with 46 chromosomes to make an identical cell. The continuity of life from one cell to another is based on the reproduction of cells via cell division, so the concept is important to understand how the human body replaces lost cells.
In order to have a full understanding of mitosis, the whole cell cycle should be understood. The cell cycle consists of four stages: G1, S, G2, and mitosis. G1, S, and G2 are subphases within interphase, and mitosis is a part of mitotic phase. The mitotic phase of the cell occurs immediately after interphase; similarly, the
…show more content…
Once a somatic cell, a living cell such as a liver cell or skin cell, has arrived at prophase, the chromosomes have already been duplicated during interphase. When prophase begins, the nucleus contains two identical sets of DNA, and the loose chromatin begins to form into an X shape that is held together by a centromere, the point on a chromosome that connects to spindle fibers. The chromatin in the shape of an X consists of two halves of DNA, and they are called mitotic chromosomes. After the mitotic chromosomes form, the centrioles move to opposite ends of the cell, and the chromosomes develop kinetochores, an attachment for spindle fibers. This part of prophase is preparing the cell for …show more content…
The chromosomes are then moved around by molecules called motor proteins. Two different proteins then pull the microtubules from one side to the other so that the chromosomes line up right down the middle at the equatorial plane. Once the chromosomes are in the middle, the pull from the proteins results in a split from the chromosomes’ copies. When the split occurs, the cell has arrived at the third phase of mitosis, anaphase.
As the split occurs, the individual chromosomes are dragged to opposite poles of the cell. The separation of the chromosomes is caused by the mitotic spindle. The mitotic spindle is made up of several long proteins called microtubules. This phase ensures that there will be an identical set of chromosomes distributed to each daughter cell. Once anaphase has occurred, the cell proceeds to the final phase of mitosis,

Related Documents