That little ball of cells: what we do with embryos depends on what we think they are.
D033421:Beginning of Human Life; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000517:prevention & control; D033041:Embryo Research / Q000941:ethics*; D005260:Female; D005307:Fertilization in Vitro / Q000941:ethics; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing / Q000941:ethics / Q000331:legislation & jurisprudence; D006801:Humans; D019836:Preimplantation Diagnosis / Q000941:ethics*; D006113:United Kingdom