The course intends to help students acquire knowledge about the biological processes underlying the beginning of life which helps to better understand the bioethical problems specific to this first phase of existence. Topics to be considered: normal fertilization, the pre-implantation embryo, the post-implantation embryo and also an introduction to other phenomena (hybridization, polyploidy, mola, mosaics/chimeras, cloning, ANT, cybrids, parthenogenesis, androgenotes, gynogenotes, teratoma and synthetic embryo) and their bioethical evaluation.