oocyte The cell that, following meiosis, forms the ovum. Most of the cytoplasmic growth involved in ovum formation is accomplished by the primary oocyte; this undergoes the first meiotic division, giving rise to two cells, the polar body, with very little cytoplasm, and the secondary oocyte, which has a large amount of cytoplasm. This latter oocyte undergoes the second meiotic division to give rise to another polar body and an ovum. Fertilization often takes place without the formation of an ovum at one of the two oocyte stages.

oocyte (oh-ŏ-syt) n. a cell in the ovary that undergoes meiosis to form an ovum. See oogenesis.

oocyte See oogenesis.