Twins Monozygotic o0-,d Zygote split 2-4 cell 2 amn 2 chorion Blastocyst 的③② ·2amn,1 chorion Bilaminar germ disc 1 amn 1 chorion Incomplete splitting · Conjoined twins on and nocent choon a parentsTwins - Monozygotic • Zygote split – 2-4 cell • 2 amn, 2 chorion – Blastocyst • 2 amn, 1 chorion – Bilaminar germ disc • 1 amn, 1 chorion – Incomplete splitting • Conjoined twins