一卵性(いちらんせい)

いちらんせい
noun
identical (twins); monozygotic
formalmedicalfamily
1. identical; monozygotic
Derived from a single fertilized egg, used primarily to describe identical twins who share the same genetic material.
一卵性(いちらんせい)双生児(そうせいじ)。
Identical twins.
二人(ふたり)は一卵性(いちらんせい)の双子(ふたご)だから見分(みわ)けがつかない。
The two are identical twins, so I can't tell them apart.
Identical twins have the same genes.

一卵性(いちらんせい) is a scientific term meaning "monozygotic" — derived from a single fertilized egg. It is almost always used as a modifier before 双子(ふたご) or 双生児(そうせいじ).

Common expressions

Similar words

  • 二卵性(にらんせい): fraternal/dizygotic (from two eggs)

Usage

双子(ふたご) alone means "twins" without specifying type. 双生児(そうせいじ) is the more formal medical term for twins. In everyday conversation, 一卵性(いちらんせい)の双子(ふたご) is more common than 双生児(そうせいじ).