title: Embryos, preembryos, and stem cells.
authors.forename: Richard
authors.initials: R
authors.lastname: Thorne
authors.forename: C Ward
authors.initials: CW
authors.lastname: Kischer
mesh_terms: D047108:Embryonic Development; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D013234:Stem Cells; D038522:Twinning, Monozygotic