Meiosis is a specialised cell division that reduces the number of chromosomes to half in each cell formed to produce four so-called haploid genetically diverse cells. In most sexually reproducing organisms, meiosis consists of two successive divisions: meiosis I and meiosis II. It enables sexual reproduction and produces genetic diversity. This type of cell division will maintain the number of chromosomes from generation to generation in sexually reproducing organisms.
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Mitosis is the kind of cell division whereby a cell divides itself to give rise to two identical daughter cells that are made up of the exact nuclear complement of their parental cell. This, therefore, is important in multicellular organisms, relating to aspects of growth, development, and tissue repair.
Introduction
Mitosis and meiosis are two major processes of cell division that give continuity to life and genetic diversity. It is here that mitosis produces identical cells with a similar type needed for growth and repair; at the same time, meiosis produces genetically unique gametes for sexual reproduction.
Cell division is a process where one parent cell divides into two or more daughter cells. It is the most crucial process for all living organisms and deals with the growth, repair, and reproduction of the organism irrespective of its type.
The essential differences among the phases of mitosis and meiosis are as follows:
Two identical daughter cells are formed
Mitosis is important for growth and proper body function.
Two daughter cells are formed from one division.
These daughter cells are genetically identical to the parent cell.
In this process, four genetically diverse cells are produced.
It is crucial for the sexual reproduction.
Four daughter cells are formed from two divisions.
The number of chromosomes in daughter cells is half the number present in parent cells.
There are four major stages of mitosis:
It involves Prophase, wherein chromosomes condense and thus become.
Metaphase, wherein chromosomes align at the cell's equatorial plate spindle fibers attach to their centromeres
Anaphase, wherein sister chromatids are pulled apart to opposite poles of the cell.
Telophase, where the cell gets ready for cytokinesis, after which two identical daughter cells are created.
Diagram illustrating each phase of mitosis
Meiosis consists of two successive divisions: Meiosis I and Meiosis II.
Meiosis I consists of Prophase I, where the pairing of the homologous chromosomes occurs and exchange their genetic materials through a process called crossing over.
Metaphase I: consists of having these pairs at the metaphase plate.
Anaphase I: the homologous chromosomes are separated into opposite poles.
Telophase I: the cell is divided into two haploid cells.
Meiosis II resembles mitosis.
Prophase II: once again compacted chromatin appears.
Metaphase II: align the chromosomes at the metaphase plate.
Anaphase II: the sister chromatids once again come to opposite poles.
Telophase II: it ends with the formation of four genetically different haploid cells.
Diagram showing the different stages of meiosis
Genetic Recombination and Crossing Over take place in Prophase I of meiosis I, when the homologous chromosomes are paired and segments of genetic material are exchanged. This shuffling of genes between the Chromosomes is known as crossing over. Its importance, however, is the fact that it leads to genetic diversity as it generates genetically variant gametes hence adding up to variations for a particular species.
Although very important, mitosis and meiosis are cell division processes with very different aims. Mitosis gives us two identical cells for growth and repair while meiosis yields four very different gametes for sexual reproduction. Both proved different in function, comparable stages include prophase, metaphase, anaphase, and telophase. This is very important knowledge in biology and genetics because here, one gets explanations about the mechanisms of growth and maintenance, genetic diversity, and inheritance.
It can be noted that mitosis produces two daughter cells that are identical to one another for growth and repair, whilst meiosis develops four gametes which are genetically diverse and meant for sexual reproduction.
While mitosis is a single, meiosis is a double division and hence yields four daughter cells. Consequently, as a result of mitosis, there remain two daughter cells.
This helps increase variation, thus the process of evolution and adaptation.
Both have the prophase, metaphase, anaphase, and telophase stages; both are cell division.
Errors in meiosis, such as nondisjunction, can cause some genetic disorders due to an abnormal number of chromosomes, as in Downs syndrome.
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