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chiasmaenUK
chi·as·ma C0283900 (kī-ăz′mə) also chi·asm (kī′ăz′əm)n. pl. chi·as·ma·ta (-mə-tə) or chi·as·mas also chi·asms 1. Anatomy A crossing or intersection of two tracts, as of nerves or ligaments.2. Genetics The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.
[Greek khīasma, cross-piece, from khīazein, to mark with an X, from khei, khī, chi (from the letter's shape).]
chi·as′mal, chi·as′mic, chi′as·mat′ic (-măt′ĭk) adj.chiasma (kaɪˈæzmə) or chiasmn, pl -mas, -mata (-mətə) or -asms1. (Genetics) cytology the cross-shaped connection produced by the crossing over of pairing chromosomes during meiosis2. (Anatomy) anatomy the crossing over of two parts or structures, such as the fibres of the optic nerves in the brain[C19: from Greek khiasma wooden crosspiece, from khiazein to mark with an X, from khi chi1] chiˈasmal, chiˈasmic adjchi•as•ma (kaɪˈæz mə) also chi•asm (ˈkaɪ æz əm)
n., pl. -as•mas, -as•ma•ta (-ˈæz mə tə) also -asms. 1. Anat. a crossing or decussation. Compare optic chiasma. 2. a point of overlap of paired chromatids at which fusion and exchange of genetic material take place during prophase of meiosis. [1830–40; < Greek: crosspiece of wood, cross-bandage =chi chi + -asma n. suffix]chi•as′mal, chi•as′mic, chi`as•mat′ic (-ˈmæt ɪk) adj. Thesaurus| Noun | 1. | chiasma - an intersection or crossing of two tracts in the form of the letter Xchiasm, decussationanatomical structure, bodily structure, body structure, complex body part, structure - a particular complex anatomical part of a living thing; "he has good bone structure"chiasma opticum, optic chiasm, optic chiasma - the crossing of the optic nerves from the two eyes at the base of the brain |
TranslationschiasmaenUK
chiasma (kīăz`mə): see crossing overcrossing over,
process in genetics by which the two chromosomes of a homologous pair exchange equal segments with each other. Crossing over occurs in the first division of meiosis. At that stage each chromosome has replicated into two strands called sister chromatids.
..... Click the link for more information. .chiasma[kī′az·mə] (anatomy) A cross-shaped point of intersection of two parts, especially of the optic nerves. (cell and molecular biology) The point of junction and fusion between paired chromatids or chromosomes, first seen during diplotene of meiosis. chiasmaenUK
chiasma [ki-az´mah] (pl. chias´mata) (L.; Gr.) chiasm.in genetics, the points at which members of a chromosome pair are in contact during the prophase of meiosis and because of which recombination, or crossing over, occurs on separation. See also formation" >chiasma formation.chi·asm (kī'azm), 1. An intersection or crossing of two lines. 2. In anatomy, a decussation or crossing of two fibrous bundles, such as tendons, nerves, or tracts. 3. In cytogenetics, the site at which two homologous chromosomes make contact (thus appearing to be crossed), enabling the exchange of genetic material during the prophase stage of meiosis. Synonym(s): chiasma [TA] [G. chiasma] chiasma (kī-ăz′mə) also chiasm (kī′ăz′əm)n. pl. chias·mata (-mə-tə) or chias·mas also chi·asms 1. Anatomy A crossing or intersection of two tracts, as of nerves or ligaments.2. Genetics The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.
chi·as′mal, chi·as′mic (-măt′ĭk), chi′as·mat′ic (-măt′ĭk) adj.chi·asm (kīazm) 1. An intersection or crossing of two lines. 2. anatomy a decussation or crossing of two fibrous bundles, such as tendons, nerves, or tracts.
Synonym(s): chiasma. 3. cytogenetics the site at which two homologous chromosomes make contact (thus appearing to be crossed), enabling the exchange of genetic material during the prophase stage of meiosis.
Synonym(s): Budd syndrome. [G. chiasma]chiasma 1. The intersection and partial crossing of the optic nerves behind the eyes within the skull. The fibres on the outer halves of each optic nerve do not cross over; those on the inner halves of each nerve do. Also known as the optic chiasm. 2. The site at which a pair of homologous chromosomes exchange material during MEIOSIS. chiasma (pl. chiasmata) the cross-shaped configuration produced during CROSSING OVER; for example, between CHROMATIDS in MEIOSIS.chi·asm , chiasma (kīazm, kī-azmă) In anatomy, decussation or crossing of two fibrous bundles, such as tendons, nerves, or tracts. [G. chiasma]chiasmaenUK
Synonyms for chiasmanoun an intersection or crossing of two tracts in the form of the letter XSynonymsRelated Words- anatomical structure
- bodily structure
- body structure
- complex body part
- structure
- chiasma opticum
- optic chiasm
- optic chiasma
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