mitosis /mi·to·sis/ (mi-to´sis) a method of indirect cell division in which the two daughter nuclei normally receive identical complements of the number of chromosomes characteristic of the somatic cells of the species.mitot´ic 
mitosis
mitosis [mi-to´sis]
)
Mitosis shown as occurring in a cell of a hypothetical animal with a diploid chromosome number of six (haploid number three); one pair of chromosomes is short, one pair is long and hooked, and one pair is long and knobbed.
mi·to·sis (m -t  s s)n. pl. mi·to·ses (-s  z) 1. The process in cell division by which the nucleus divides, typically in four stages (prophase, metaphase, anaphase, and telophase) resulting in two new nuclei, each of which has exactly the same chromosome and DNA content as the original cell. Also called indirect nuclear division, karyokinesis, mitotic division. 2. The entire process of cell division including division of the nucleus and the cytoplasm. mi·tot ic (-t tk) adj.mi·tot i·cal·ly adv. |  |
mitosis
[mītō′sis, mit-]
Etymology: Gk, mitos, thread
a type of cell division that occurs in somatic cells and results in the formation of two genetically identical daughter cells containing the diploid number of chromosomes characteristic of the species. It consists of the division of the nucleus followed by the division of the cytoplasm. The former has four stages (prophase, metaphase, anaphase, and telophase), during which the two chromatids of each chromosome separate and migrate to opposite ends of the cell. Mitosis is the process by which the body produces new cells for both growth and repair of injured tissue. Kinds of mitosis are heterotypic mitosis, homeotypic mitosis, multipolar mitosis, and pathologic mitosis. Also called indirect division. Compare meiosis. See also interphase. mitotic, adj.
mitosis [mi-to´sis]
the ordinary process of cell division resulting in the formation of two daughter cells, by which the body replaces dead cells. The daughter cells have identical diploid complements of chromosomes (46 in human somatic cells). Cell division that results in haploid reproductive cells is known as meiosis. The period between mitotic divisions is called interphase, and mitosis itself occurs in four phases: prophase, metaphase, anaphase, and telophase. adj., adj mitot´ic.
During interphase the chromosomes are extended long threads that cannot be visibly identified. The DNA of the chromosomes is replicated during this phase, resulting in duplication of the genetic material.
During prophase the chromosomes coil up and contract, becoming short rods. Each chromosome consists of a pair of strands, called chromatids, held together at the centromere. At the same time the nuclear envelope disappears, and the centriole divides and the two daughter centrioles move toward opposite poles of the cell.
During metaphase the chromosomes move so that their centromeres are aligned in the equatorial plane of the cell (the metaphase plate), and the mitotic spindle forms. The mitotic spindle is formed of fibers composed of microtubules, which extend from the centrioles to the metaphase plate and to the centromeres of the chromosomes.
During anaphase the chromatids of each chromosome separate, becoming new daughter chromosomes, which are drawn to opposite poles of the cell by the spindle fibers.
During telophase the daughter chromosomes arrive at the poles of the cell, where they are surrounded by two new nuclear envelopes as they begin to uncoil and extend. During this phase, cytokinesis, division of the cytoplasm, occurs. A furrow forms around the cell in the equatorial plane and deepens until the two daughter cells are separated.
Originally, the term mitosis referred only to the division of the nucleus, which can occur without cytokinesis in certain fungi and in the fertilized eggs of insects. As used now, it usually refers to mitotic cell division.
During interphase the chromosomes are extended long threads that cannot be visibly identified. The DNA of the chromosomes is replicated during this phase, resulting in duplication of the genetic material.
During prophase the chromosomes coil up and contract, becoming short rods. Each chromosome consists of a pair of strands, called chromatids, held together at the centromere. At the same time the nuclear envelope disappears, and the centriole divides and the two daughter centrioles move toward opposite poles of the cell.
During metaphase the chromosomes move so that their centromeres are aligned in the equatorial plane of the cell (the metaphase plate), and the mitotic spindle forms. The mitotic spindle is formed of fibers composed of microtubules, which extend from the centrioles to the metaphase plate and to the centromeres of the chromosomes.
During anaphase the chromatids of each chromosome separate, becoming new daughter chromosomes, which are drawn to opposite poles of the cell by the spindle fibers.
During telophase the daughter chromosomes arrive at the poles of the cell, where they are surrounded by two new nuclear envelopes as they begin to uncoil and extend. During this phase, cytokinesis, division of the cytoplasm, occurs. A furrow forms around the cell in the equatorial plane and deepens until the two daughter cells are separated.
Originally, the term mitosis referred only to the division of the nucleus, which can occur without cytokinesis in certain fungi and in the fertilized eggs of insects. As used now, it usually refers to mitotic cell division.
Mitosis shown as occurring in a cell of a hypothetical animal with a diploid chromosome number of six (haploid number three); one pair of chromosomes is short, one pair is long and hooked, and one pair is long and knobbed. From Dorland's, 2000.
mitosis,
n a type of cell division that occurs in somatic cells and results in the formation of two genetically identical daughter cells containing the diploid number of chromosomes characteristic of the species.
mitosis
the ordinary process of cell division which results in the formation of two daughter cells, and by which the body replaces dead cells. The two daughter cells receive identical diploid complements of chromosomes, which are characteristic of somatic cells. Cell division that results in haploid reproductive cells is known as meiosis. The period between mitotic divisions is called interphase. Mitosis itself occurs in four phases: prophase, metaphase, anaphase and telophase.
Originally, the term mitosis referred only to the division of the nucleus, which can occur without cytokinesis in certain fungi and in the fertilized eggs of insects. As used now, it usually refers to mitotic cell division.
mitosis
Process by which a cell nucleus divides into two nuclei with chromosome numbers and genetic make-up identical to that of the parent cell. Mitosis is inhibited by anaesthetics and thus tissue repair is delayed. It is also slowed by hypoxia. Example: the mitosis of the basal cells of the corneal epithelium; the mitosis of the epithelial cells of the crystalline lens adding new cells to it which eventually form new lens fibres. See apoptosis; chromosome; corneal abrasion; Krebs cycle.
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