chiasma

noun chi·as·ma \ kī-ˈaz-mə , kē- \

Definition of chiasma

plural chiasmata play \kī-ˈaz-mə-tə, kē-\

1 : an anatomical intersection or decussation — compare optic chiasma

2 : a cross-shaped configuration of paired chromatids visible in the diplotene stage of meiotic prophase and considered the cytological equivalent of genetic crossing-over

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chiasmatic

play \ˌkī-əz-ˈma-tik, ˌkē-\ adjective

Origin and Etymology of chiasma

New Latin, X-shaped configuration, from Greek, crosspiece, from chiazein to mark with a chi, from chi (x)

NEW! Time Traveler

First Known Use: 1839

in the meaning defined at sense 1

See Words from the same year

Medical Dictionary

chiasma

noun chi·as·ma \ kī-ˈaz-mə, kē- \

medical Definition of chiasma

plural chiasmata play \-mət-ə\

1 : an anatomical intersection or decussation — see optic chiasma

2 : a cross-shaped configuration of paired chromatids visible in the diplotene of meiotic prophase and considered the cytological equivalent of genetic crossing-over

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