Online Google Dictionary

chiasma 中文解釋 wordnet sense Collocation Usage Collins Definition
Noun
/kīˈazmə/,
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chiasmata, plural;
  1. A point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occur between the strands

  1. an intersection or crossing of two tracts in the form of the letter X
  2. A chiasma (plural: chiasmata), in genetics, is thought to be the point where two homologous non-sister chromatids exchange genetic material during chromosomal crossover during meiosis (sister chromatids also form chiasmata between each other, but because their genetic material is identical, it ...
  3. A crossing of two nerves, ligaments etc; The contact point between the two chromatids of a chromosome during meiosis
  4. The cytologically visible consequence of a reciprocal recombination event in meiosis, observable in the later stage of meiotic prophase. Chiasmata hold homologous chromosomes together prior to anaphase of the first meiotic division.
  5. The site where the exchange of chromosome segments between homologous chromosomes takes place (crossing-over) (pl.: chiasmata). PICTURE
  6. An anatomy term for an X-shaped crossing (for example, of nerves or tendons).
  7. (French : chiasma) Exchange sites between chromatids observed in prophase of meiosis 1 subsequent to crossing over.
  8. Greek kiasma = cross. (The Greek letter chi = c).
  9. The cross-like structure formed by crossing over during meiosis.
  10. A crossing of nerve tracts from one side of the CNS to the other; also called a chiasm.
  11. The physical crossover point between pairs of homologous chromosomes in the process of recombination that can be observed during the diplotene and diakinetic stages of prophase 1 and during metaphase 1 of meiosis.