Binary Fission, Mitosis, and Meiosis, Essay Example

Compare and contrast binary fission, mitosis, and meiosis. Please include a discussion of their prevalence within their domains of life and the advantages/disadvantages for each approach of cell division

Cells can divide. In unicellular organisms, this makes more organisms. In multicellular organisms this is used for growth, development, and repair.

Binary fission is the asexual reproduction of a cell which only takes place in prokaryotes. Before this can occur, a cell must replicate its chromosome. This starts when a replication bubble opens within the DNA. There is normally only a single origin of replication, unlike that of Eukaryotes. As the bubble increases in size, the DNA strands become longer. DNA polymerase converts each of these strands into double strands and two circular chromosomes are produced. They then affix to the cell membrane, move apart, and pass into each of the daughter cells.

Mitosis is the process of division of chromosomes. There are five stages in the process. Interphase is the resting phase, however, at this stage replication of chromosomes and cell growth are still taking place. In prophase the chromosomes start to coil, shorten and become distinct. The mitotic spindle also starts to form. In animals, centrioles begin to move toward the poles of the cell. In metaphase, the chromosomes begin to line up along the equator of the cell. In anaphase, the chromatids separate at the centromeres and are pulled to the poles of the cell. Telophase takes place when the new daughter nuclei and nuclear envelopes start to reform and chromosomes uncoil. This is also the start of cytokinesis. Cytokinesis happens only in mitosis. In animals it happens in the cleavage furrow and in plants it happens in the cell plate.

The significance of cell division in mitosis and binary fission is that they produce two cells that are identical to the parent cell. In unicellular organisms, this is asexual production. In multicellular organisms these processes help with growth and repair and asexual reproduction.Meiosis is present in sexual reproduction. Again meiosis goes through the same phases as Mitosis, but there are multiple of each phase. The phases do differ somewhat. The differences between mitosis and meiosis are that meiosis occurs in germinal tissues. Meiosis involves two successive nuclear divisions in which the chromosomes are duplicated only once. The two divisions are termed meiosis one and meiosis two, which explains why there are multiples of each stage in the process. At the completion of meiosis there are four daughter cells, instead of two like that of mitosis. The daughter cells are genetically different due to crossing over and independent assortment, unlike in mitosis and binary fission where the daughter cells are identical.