chiasma

詳細解釋：

chi.as.ma

n.（名詞）
【複數】 chi.as.ma.ta[-m…-t…] 或 chi.as.mas 也作 chi.asms
Anatomy A crossing or intersection of two tracts, as of nerves or ligaments.
【解剖學】 視神經交叉：如神經或韌帶等兩束相交或橫斷
Genetics The point of contact between paired chromatids during meiosis, resulting in a cross-shaped configuration and representing the cytological manifestation of crossing over.
【遺傳學】 染色體交叉：在減數分裂過程中成對的染色體之間的接觸點產生一種交叉形狀的構造，代表著基因互相交換的細胞表現形式

來源：
Greek khiasma [cross-piece]
希臘語 khiasma [橫桿]
from khiazein [to mark with an X]
源自 khiazein [用X作標記]
from khi [chi (from the letter`s shape)]
源自 khi [chi（來自字母X的形狀）]

【引伸】
chias.mal 或
chias.mic 或
chi.asmat.ic