Human Conception and the Status of Single–Celled Human Zygote from the Perspective of Catholic Bioethics

In the discussions on the status of human zygote, the issue of its animation appears only occasionally. Current teaching of the Magisterium of the Church on the beginning of human life emphasises the fact that life of a new human being begins with the conception. The moment when single 2n diploid cell called zygote comes into being is very often considered as a start of a new human life. According to embryology, this takes place 12 to 24 hours after fertilization. The discoveries in epigenetics allow to claim the human character of a zygote is then defined. From the moment of conception, that is when the head of spermatozoon combines with oocyte cytoplasm and two pronuclei come into existence (the nuclei of both male and female gametes), the processes related to a new human life begin.