Before revision: (A) oogonium where the mitotic division occurs (B) differentiation and meiosis I begins (C) primary oocyte (D) meiosis I is completed and meiosis II begins (E) secondary oocyte (F) first polar body (G) ovulation must occur and the presence of the sperm penetration (fertilization) induces meiosis II to completion (H) ovum (I) second polar body thumb Human oogenesis Oogenesis throughout a woman's life Oogenesis Oogenesis starts with the process of developing primary oocytes, which occurs via the transformation of oogonia into primary oocytes [ , a process called oocytogenesis.
After revision: (A) oogonium where the mitotic division occurs (B) differentiation and meiosis I begins (C) primary oocyte (D) meiosis I is completed and meiosis II begins (E) secondary oocyte (F) first polar body (G) ovulation must occur and the presence of the sperm penetration (fertilization) induces meiosis II to completion (H) ovum (I) second polar body thumb Human oogenesis Oogenesis throughout a woman's life Oogenesis Oogenesis starts with the process of developing primary oocytes, which occurs via the transformation of oogonium|oogoniainto primaryoocytes [ , a process called oocytogenesis.