Cell division and reproduction can occur in two ways - mitosis and meiosis.
Mitosis is a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells.
Meiosis, on the other hand, is a division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex cells, each possessing half the number of chromosomes of the original cell.
Mitosis is used by single celled organisms to reproduce; it is also used for the organic growth of tissues, fibers, and membranes. Meiosis is useful for sexual reproduction of organisms. The male and female sex cells, e.g. the spermatozoa and egg, fuse to create a new, singular biological organism.
|Definition||A type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of homologous chromosomes, producing two haploid cells.||A process of asexual reproduction in which the cell divides in two producing a replica, with an equal number of chromosomes in each resulting diploid cell.|
|Function||sexual reproduction||Cellular Reproduction & general growth and repair of the body|
|Type of Reproduction||Sexual||Asexual|
|Occurs in||Humans, animals, plants, fungi||all organisms|
|Crossing Over||Yes, mixing of chromosomes can occur.||No, crossing over cannot occur.|
|Pairing of Homologs||Yes||No|
|Number of Divisions||2||1|
|Number of Daughter Cells produced||4 haploid cells||2 diploid cells|
|Chromosome Number||Reduced by half||Remains the same|
|Steps||The steps of meiosis are Interphase, Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II and Telophase II.||The steps of mitosis are Interphase, Prophase, Metaphase, Anaphase, Telophase and Cytokinesis|
|Karyokinesis||Occurs in Interphase I||Occurs in Interphase|
|Cytokinesis||Occurs in Telophase I & Telophase II||Occurs in Telophase|
|Centromeres Split||The centromeres do not separate during anaphase I, but during anaphase II||The centromeres split during Anaphase|
|Creates||Sex cells only: Female egg cells or Male sperm cells||Makes everything other than sex cells|
|Discovered by||Oscar Hertwig||Walther Flemming|
Mitosis is a method of reproduction for single celled organisms that reproduce asexually. An identical version of the organism is created through splitting of the cell in two. Meiosis may result in millions of spermatozoa and egg cells with unique genetic patterns. The mating of the two cells formed by meiosis results in a unique genetic offspring of the same species. Meiosis is a major factor in evolution, natural selection, and biodiversity. The processes of cellular division shown in mitosis and meiosis are present in all manner of life forms including humans, animals, plants, fungi, and single celled organisms and species. Essentially any cell based organism of which all organic life is based will exhibit some form of mitosis and meiosis for growth and reproduction of the individual and species.
Different Stages of Mitosis and Meiosis
The different phases of meiosis are: Prophase, Metaphase, Anaphase and Telophase.
This video explains the stages of mitosis and meiosis in more detail:
Differences in Purpose
Both Meiosis and Mitosis are found in complex organisms which reproduce sexually. Mitosis may be used for human growth, the replenishment of depleted organs and tissues, healing, and sustenance of the body. Identical versions of cells can be created to form tissues through Mitosis. Meiosis is a special process reserved for the creation of the egg and sperm cells. The same patterns may be found in many species of plant and animal cell reproduction.
The importance of mitosis is the maintenance of the chromosomal set; each cell formed receives chromosomes that are alike in composition and equal in number to the chromosomes of the parent cell.
Meiosis is found to occur in humans, animals and plants while mitosis is found in single-cell species as well.
Walther Flemming discovered the process of Mitosis in 1882.
Mitosis as a form of reproduction for single-cell organisms originated with life itself (around 4 billion years ago). Meiosis is thought to have appeared 1.4 billion years ago.
Chromosomal pattern comparison
In mitosis, each daughter cell ends up with two complete sets of chromosomes while in meiosis, each daughter cell ends up with one set of chromosomes.
Both mitosis and meiosis are studied by scientists generally by using a microscope to identify and classify chromosomal patterns and relationships within the cell’s structure. An understanding of the way cells synthesize chromosomes for reproduction can be applied in bio-machines and nano-technology. Transplantation of genes and chromosomes through injection and implantation is used to experiment with bio-engineering and cloning. Understanding the process through which cells replicate also has application in medicine and the study of health and disease.