primitive streak

Noun

(embryology) A formation that occurs during the initial phases of embryonic development in birds, reptiles and mammals.

Japanese Meaning

（胚発生学）鳥類、爬虫類、哺乳類などの胚発生初期に出現する、細胞が帯状に集まった構造（原始線）

The researcher examined the primitive streak under the microscope to study the origin of the germ layers.

研究者は胚葉の起源を研究するために、顕微鏡で胚の原始線条を観察した。

Sense（1）

(embryology) A formation that occurs during the initial phases of embryonic development in birds, reptiles and mammals.

primitive streaks

（ plural ）