Oogenesis
（重定向自Ootidogenesis）
![Diagram showing the reduction in number of the chromosomes in the process of maturation of the ovum. (In mammals, the first polar body normally disintegrates before dividing, so only two polar bodies are produced.)](/Images/godic/202501/31/Gray5.svg5233.png")
Oogenesis, ovogenesis, or oögenesis /ˌoʊ.əˈdʒɛnᵻsɪs/ is the creation of an ovum (egg cell). It is the female form of gametogenesis; the male equivalent is spermatogenesis. It involves the development of the various stages of the immature ovum.