GED Science: Binary Fission
As cells in your body age, they die, and need to be replaced. Cells in different locations in the body have different life spans. For example, cells lining the digestive tract survive about 3-5 days, while red blood cells survive about 120 days. Remember that according to the cell theory, cells can only arise from other cells. There are two main ways that cells can make copies of themselves: binary fission and mitosis.
Binary fission is the process in which one prokaryotic cell divides to make two prokaryotic cells. Remember that prokaryotic cells have genetic information, but that this information is stored floating around in the cytoplasm, rather than contained in a nucleus, like in eukaryotic cells. The genetic information in a prokaryotic cell is found in a circular chromosome. Basically, binary fission requires that the circular chromosome be duplicated, that the two copies of the chromosome attach to the plasma membrane, and that the cell pinch in the middle to divide into two daughter cells. Often, the beginning cell in the process is called the parent cell, while the two cells resulting from binary fission are called daughter cells. The following diagram shows binary fission:
Remember that the chromosome contains the genetic information in a cell. The fact that the chromosome is duplicated exactly from the parent cell means that both daughter cells will be genetically identically to each other and to the parent cell.