mitosis


mitosis
The usual process of nuclear division in the somatic cells of eukaryotes. Mitosis is classically divided into four stages. The chromosomes are actually replicated prior to mitosis during the S phase of the cell cycle. During the first stage, prophase, the chromosomes condense and become visible as double strands (each strand being termed a chromatid) and the nuclear envelope breaks down. At the same time the mitotic spindle forms by the polymerization of microtubules and the chromosomes are attached to spindle fibres at their kinetochores. In metaphase the chromosomes align in a central plane perpendicular to the long axis of the spindle. This is termed the metaphase plate. During anaphase the paired chromatids are apparently pulled to opposite poles of the spindle by means of the spindle fibre microtubules attached to the kinetochore, though the actual mechanism for this movement is still controversial. This separation of chromatids is completed during telophase, when they can be regarded as chromosomes proper. The chromosomes now lengthen and become diffuse and new nuclear envelopes form round the two sets of chromosomes. This is usually followed by cell division or cytokinesis in which the cytoplasm is also divided to give two daughter cells. Mitosis ensures that each daughter cell has a diploid set of chromosomes that is identical to that of the parent cell.

Dictionary of molecular biology. 2004.

Look at other dictionaries:

  • mitosis — f. citol. Tipo de división celular en la que a partir de una célula se forman dos células hijas con la misma dotación cromosómica que la progenitora. La mitosis comprende cuatro fases: profase, metafase, anafase y telofase. En la profase… …   Diccionario médico

  • mitosis — (plural mitosis) sustantivo femenino 1. Área: biología Proceso de reproducción celular en el que mediante la división de la célula madre se originan dos células hijas con el mismo número de cromosomas e igual información genética …   Diccionario Salamanca de la Lengua Española

  • Mitosis — Mi*to sis, n. [NL., fr. Gr. ? a thread.] (Biol.) See {Karyokinesis}. [1913 Webster] …   The Collaborative International Dictionary of English

  • mitosis — mitosis. См. непрямое деление. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • mitosis — (n.) 1887, coined in German from Gk. mitos warp thread (see MITRE (Cf. mitre)) + Mod.L. osis act, process. Term introduced by German anatomist Walther Fleming (1843 1905) in 1882. So called because chromatin of the cell nucleus appears as long… …   Etymology dictionary

  • mitosis — (Del gr. μιτοῦν, tejer, y sis). f. Biol. División de la célula en la que, previa duplicación del material genético, cada célula hija recibe una dotación completa de cromosomas …   Diccionario de la lengua española

  • mitosis — ► NOUN (pl. mitoses) Biology ▪ a type of cell division in which daughter cells have the same number and kind of chromosomes as the parent nucleus. Compare with MEIOSIS(Cf. ↑meiotic). ORIGIN from Greek mitos thread …   English terms dictionary

  • mitosis — [mī tō′sis, mitō′sis] n. pl. mitoses [mī tō′sēz΄, mi tō′sēz΄] [ModL < Gr mitos, thread + OSIS] Biol. the indirect and more common method of nuclear division of cells, consisting typically of prophase, metaphase, anaphase, and telophase: the… …   English World dictionary

  • Mitosis — Not to be confused with meiosis, miosis, or myositis. Mitosis divides the chromosomes …   Wikipedia

  • Mitosis — Micrografía de una célula mitótica pulmonar de tritón. Cromosomas homólogos en mitosis (arriba) y me …   Wikipedia Español

  • mitosis — mitotic /muy tot ik/, adj. mitotically, adv. /muy toh sis/, n. Cell Biol. the usual method of cell division, characterized typically by the resolving of the chromatin of the nucleus into a threadlike form, which condenses into chromosomes, each… …   Universalium


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