Meiosis Vs. Mitosis

More than one celled organisms grow by way of mitosis and the cytoplasmic division of body cells. On the other hand, meiosis occurs only in germ cells, which are put aside for the formation of gametes (sperm and egg). Reproduction by meiosis allows for species survival and it increases genetic variability.

The process, during which the germ cells are generated is called meiosis. It represents nature's solution to the problem of chromosome doubling that would occur, if two diploid cells, i.e. two cells with a double set of chromosomes would fuse. Accordingly does meiosis produce haploid germ cells, with maternal and paternal germ cell fusing at fertilization and thus generating a diploid fusion product, the zygote. Meiosis is made up by two subsequent processes, both of which resemble mitosis. In the first process are the homologous chromosomes separated. It has an unusually long prophase that is subdivided into different stages They are followed by metaphase, anaphase and telophase.

Two nuclei fuse upon fertilization, so that the number of chromosomes does necessarily double. If this thought is spun further, would an greater growth of the number of chromosomes from generation to generation have to be expected. This is not the case, because the chromosomes are reduced to half their normal number in germ cell production. This process is called meiosis. It consists of two successive mitosis-like divisions: in the first division is the number of chromosomes reduced to their half, the second is a normal mitosis.

Each germ cell contains a complete set of chromosomes, a haploid set. Accordingly are the cells haploid and zygotes and the body cells that stem from them are diploid, because they contain two equal sets of chromosomes, one from the mother and one from the father. They exist, especially in plants.

At the beginning of meiosis, in prophase 1 the plate breaksdown and chromosomes become visible as in mitosis (1). The chromosomes have replicated but individual chromatids are not visible. Instead of lining up on a metaphase, as in mitosis, chromosomes come together in pairs (2). Each chromosome in a pair is similar in structure (homologous), but would have come originally from different parents. Later in propha...

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...hese daughter chromosomes then begin to separate from each other, each moving away from the metaphase plate and toward one of the two spindle pole regions. The mechanisms that control chromosome separation clearly involve the interactions between microtubules and components in or near the kinetochore.

Sometime after anaphase onset, the chromosomes have moved close to the spindle pole regions, and the spindle middle begins to clear. In this middle region of the spindle, a thin line of vesicles begins to grow. The vesicle aggregation event is a harbinger to the assembly of a new cell wall that will be positioned midway along the length of the original cell. It will form the boundary between the newly separating daughter cells. This basket shaped structure forms in late anaphase or early telophase and breaksdown about the time that the vesicles begin to grow.

In Meiosis and Meitosis we deal with many of the same stages that it takes to create a new life form. Cell Division in meiosis and meitosis are very similar in that they can create and vary cell formation to adapt to certain applications,