Mitosis And Meiosis Reproduction In Eukaryotic Cells
Both meiosis, or mitosis, are different types of reproduction found in eukaryotic cell cells. Both of these processes can be similar, but they are different in other aspects. Both can result in new cells being created, though they do so using different methods. A type of asexual reproductive technology, meiosis a type. Both of these processes are essential for the survival and growth of organisms and cells. A process of nuclear divide in eukaryotic cell is called mitosis. This involves the formation of two daughter cells, which are genetically identical to their parent cells. It preserves the number of chromosomes by providing equal amounts of duplicated chromosomes for each daughter nucleus.
Mitosis’ main purpose is to asexually reproduce, grow, and regenerate cells in the somatic cells or body cells. The five phases of mitosis are prophase, metaphase (prometaphase), prophase, anaphase, telophase, and metaphase. The mitotic spindle forms when tightly coiled, chromatin is condensed into chromosomes. The nucleolus also disappears in prophase. However, the nucleus remains intact. Next will be prometaphase. This is when the nuclear shell fragments and spindle-microtubules attaches to the chromosomes’ kinetochores. The mitotic spundle is completed in metaphase. The chromosomes are attached at the microtubules of the kinetochores and will align at metaphase. Anaphase is a phase in which the chromatids and daughter chromosomes move to opposite poles of a cell. Telophase is the end of mitotic phases. Two daughter nuclei develop. Cytokinesis often overlaps with late-telophase. Two diploid daughters cells are created from the genetic material of their parent cells. This is called mitosis. Since the genetic material within the daughter cells does not change, there is no genetic variability in mitosis. Meiosis refers to a modified method of cell division for sexually reproducing organisms. It includes two rounds in cell division and only one round for DNA replication. End result: The cell has half the number as the original. Meiosis is used to produce genetic diversity by means of sexual reproduction. Eukaryotic cells such as animals, plants and fungi undergo chromosomal loss. This leads to the formation of sex cells. The reduction in chromosome numbers would prevent the merging two gametes in fertilization, which would result in offspring that have twice as many chromosomes. Meiosis comprises two sub-divisions.
Meiosis one focuses only on the reduction or conversion of chromosomes. Meiosis two focuses more on the separation and recombination of sister cells. Meiosis II begins with prophase 1 which contains five stages. This phase includes the condensing of chromatin into DNA, the breakdown of the nuclear envelope and synapsis between the chromosomes of each pair. Recombinant chromosomes are created by crossing over. These chromosomes contain combined genes that have been inherited from both parents. Metaphase 1 continues with the random arrangement of tetrads in the metaphase plate. It is not possible to align individual chromosomes like mitosis. Anaphase I sees the homologous and duplicated chromosomes move to opposite poles, while the sister chromatids remain attached. Telophase II is the next phase, where the spindle filaments continue to move to the opposite poles. After the poles are complete, they each contain a number of haploid chromosomes.
Cytokinesis overlaps at this stage. The cell produces two daughters cells that have half the number as the parent. The cell will enter Meiosis II by starting prophase II. This phase is marked by the formation and shifting of chromosomes to the metaphase I plate. Metaphase II is the continuation of the alignment chromosomes to the metaphase plates. The kinetochores sister chromatids have attached microtubules. They extend from opposite poles. Anaphase II sees sister-chromatids breaking apart and moving towards opposite poles. This is done by the elongation nonconnected spindle fibers. These sister chromatids that have separated are now called daughter chromosomes. Meiosis II concludes with telophase I, when nuclei develop and chromosomes decondense. Cytokinesis is the next step, which results in four haploid daughters cells that are genetically different from their parent cells. This genetic variation is caused independent of homologous DNA chromosomes as well as non-identical sister cells.
Although they are distinct processes, meiosis is similar to mitosis. Interphase must take place before either of these processes can begin. The G1 and G2 phases define interphases. Cell growth takes place during the G1-G2 phases, while DNA replication takes effect in the S Phase. These are necessary for the cell’s ability to undergo meiosis and mitosis. These two processes both start with a diploid cell parent, though their outcomes will vary. Each stage of meiosis or mitosis is the same: prophase to metaphase, anaphase to telophase, then cytokinesis. These stages will not change despite the differences between each step. Another commonity between mitosis/meiosis is that chromatin is condensed into chromosomes. Prophase is the first stage in which chromosomes are visible.
