NCBI ROFL: Self-fertilization in human: Having a male embryo without a father.

"Chimeras are the result of fusion of two zygotes to form a single embryo, producing an individual with genetically different kinds of tissue. If the fused zygotes are of different sex, the individual develops both ovarian and testicular tissues. The majority of these people are best reared as females and many pregnancies with living offspring have been reported in persons reared as females, and several cases has fathered a child. During ovulation, a negative pressure occurs in the lumen of the oviduct and it produces a vacuum effect which has made several pregnancies possible in subjects lacking an ipsilateral ovary by allowing the transperitoneal migration of oocyte from the contralateral gonad. Self-fertilization was reported in many flowering plants, in a kind of fish and in a case of rabbit. They have both eggs and sperms in their body and at fertilization, one sperm cell fuses with oocyte to form an ...