MeSH definition : Two off-spring from the same PREGNANCY. They are from a single fertilized OVUM that
split into two EMBRYOS. Such twins are usually genetically identical and of the same
sex.;
Two off-spring from the same PREGNANCY. They are from a single fertilized OVUM that
split into two EMBRYOS. Such twins are usually genetically identical and of the same
sex.
http://campus.cerimes.fr/histologie-et-embryologie-medicales/enseignement/embryo_7/site/html/1.html http://campus.cerimes.fr/histologie-et-embryologie-medicales/enseignement/embryo_7/site/html/cours.pdf true France French educational course embryology twins, dizygotic twins, monozygotic cleavage stage, ovum embryonic structures embryonic development