Virgin Mary gave birth to Jesus without a father. A scenario is presented here for this miraculous event. She is a chimera of 46,XX/46,XY type resulting from the fusion of two embryos of different sex types and both ovary and testis develop in Her body. It is well known that in chimera XX cells tend to gather on the left side while XY cells on the right; therefore, an ovary develops at the left side with an oviduct and a testis develops at the right side of the abdominal cavity with no duct. Both gonads are functional and produce oocyte and spermatozoa respectively after puberty. At the time of ovulation, estrogens leads to a negative pressure in the left oviduct and this vacuum effect helps oocyte and sperms to be picked-up into the tube, taking both types of gametes to the fertilization site in the left oviduct. Because of the higher temperature of the oocyte at the left ovary, fertilization occurs with a Y-bearing sperm to give rise to a XY male embryo which becomes miraculously Jesus.
Key words: Chimera; Fertilization; Virgin birth