This only one secondary follicle. This is known

This is the development/maturity of the ovum (female gametes) from the oogonia that occur under meiosis. The development of the ovum begins shortly after the foetus has started to grow. The process of oogenesis goes through three phases; multiplication, growth and maturation
In the multiplication phase, during foetal development, some cells in the ovary are significantly larger than the others Thus, cells start to divide by a process known as mitosis. This cell division produces many more other oogonia in each ovary of the foetus. However, after birth, these cells can no longer be produced. This is a process called oocytogenesis. Once this is complete, primary oocytes will be formed, and they can then complete full maturation through meiotic division.
During follicle development, the menstrual cycle is stimulated to begin. At the start of this cycle, follicle-stimulating hormone is mass produced and released to stimulate the development of primary follicles. As a result, this will form secondary follicles and the primary follicles, which are developed in the ovary as a foetus, are stored during conception in the prophase state of the cellular cycle. On day 9 of the menstrual cycle, most of the secondary follicle will be absorbed into the ovary, leaving only one secondary follicle. This is known as the dominant follicle. Its role is mainly to mass produce estrogen during the late follicular phase. During day 14 of the menstrual cycle, positive feedback of estrogen stimulates the release of luteinizing hormone. The secondary follicle is then developed into a tertiary follicle. Also, during the transformation of the tertiary follicle, the primary oocytes complete their first meiotic division. As a result of this, a polar body and secondary oocyte is formed. The empty follicle then forms a corpus luteum which later releases progesterone to maintain pregnancy (if it happens).
After the first stage of meiosis, the haploid secondary oocyte initiates the second stage of meiotic divison. However, this process is inhibited at the second stage of metaphase until fertilization occurs. When meiosis has completed, an ootid and another polar body is created. Both polar bodies disintegrate at the end of second meiotic divison, leaving only the ootid, which eventually develops into a mature ovum, while the haploid egg cell becomes ready for the fertilisation.