| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024chi•as•ma (kī az′mə),USA pronunciation n., pl. -mas, -ma•ta (-mə tə).USA pronunciation - Anatomya crossing or decussation, as that of the optic nerves at the base of the brain.
- [Cell Biol.]a point of overlap of paired chromatids at which fusion and exchange of genetic material take place during prophase of meiosis.
Also, chi•asm (kī′az əm).USA pronunciation - Greek: crosspiece of wood, cross-bandage, equivalent. to chi chi1 + -asma noun, nominal suffix
- 1830–40;
Collins Concise English Dictionary © HarperCollins Publishers:: chiasma /kaɪˈæzmə/ n ( pl -mas, -mata / -mətə/, -asms)- the cross-shaped connection produced by the crossing over of pairing chromosomes during meiosis
- the crossing over of two parts or structures, such as the fibres of the optic nerves in the brain
Etymology: 19th Century: from Greek khiasma wooden crosspiece, from khiazein to mark with an X, from khi chi1 |