| 释义 |
nondisjunction
non·dis·junc·tion N0137800 (nŏn′dĭs-jŭngk′shən)n. The failure of paired chromosomes or sister chromatids to separate and go to different cells during meiosis.
non′dis·junc′tion·al adj.nondisjunction (ˌnɒndɪsˈdʒʌŋkʃən) n (Genetics) the failure of paired homologous chromosomes to move to opposite poles of the cell during meiosisThesaurus| Noun | 1. | nondisjunction - meiosis in which there is a failure of paired homologous chromosomes to separate; results in an abnormal number of chromosomes in the daughter cellsmeiosis, miosis, reduction division - (genetics) cell division that produces reproductive cells in sexually reproducing organisms; the nucleus divides into four nuclei each containing half the chromosome number (leading to gametes in animals and spores in plants) |
nondisjunction
nondisjunction[¦nän′dis‚jaŋk·shən] (genetics) Failure of homologous chromosomes to separate symmetrically during cell division, with both ending up in the same daughter cell instead of in each daughter cell. nondisjunction
nondisjunction [non″dis-jungk´shun] failure either of two homologous chromosomes to pass to separate cells during the first meiotic division, or of the two chromatids of a chromosome to pass to separate cells during mitosis or during the second meiotic division. As a result, one daughter cell has two chromosomes or two chromatids, and the other has none. If this happens during meiosis, an aneuploid individual (for example, a child with Down syndrome) may develop following fertilization. Nondisjunction. Normal meiosis (A) is contrasted with failure of homologous chromosomes to separate in meiosis I (B) or of sister chromatids to separate in meiosis II (C). From Dorland's, 2000.non·dis·junc·tion (non'dis-jŭnk'shŭn), [MIM*257300] Failure of one or more pairs of chromosomes to separate at the meiotic stage of karyokinesis, with the result that both chromosomes are carried to one daughter cell and none to the other.nondisjunction (nŏn′dĭs-jŭngk′shən)n. The failure of paired chromosomes or sister chromatids to separate and go to different cells during meiosis.
non′dis·junc′tion·al adj.non·dis·junc·tion (non'dis-jŭngk'shŭn) Failure of one or more pairs of chromosomes to separate at the meiotic stage of karyokinesis, with the result that both chromosomes are carried to one daughter cell and none to the other.  NONDISJUNCTIONnondisjunction (nŏn″dĭs-jŭnk′shŭn) The failure of a pair of chromosomes to separate during meiosis, allowing one daughter cell to have two chromosomes and the other to have none. See: illustration Fig. 230 Nondisjunction . (a) Normal disjunction (b) Nondisjunction. nondisjunction the failure of chromosomes (in eukaryotes) to go to opposite poles during nuclear division, leading to unequal numbers of chromosomes in the daughter cells (see ANEUPLOIDY). See Fig. 230 . Nondisjunction produces abnormal numbers of both AUTOSOMES (e.g. DOWN'S SYNDROME) and SEX CHROMOSOMES (e.g. TURNERS SYNDROME).NondisjunctionA genetic term referring to an event which takes place during cell division, in which a genetic accident causes an egg or sperm cell to have 24 chromosomes, rather than the normal 23.Mentioned in: Down Syndromenondisjunction
Words related to nondisjunctionnoun meiosis in which there is a failure of paired homologous chromosomes to separateRelated Words- meiosis
- miosis
- reduction division
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