Which of the following statements is correct with respect to the process of oogenesis?
I. Primary follicle can also be defined as primary oocyte with layers of granulosa cells
II. Corpus albicans on degeneration produces progesterone that helps during early pregnancy
III. Graafian follicles have well developed and large fluid-filled cavity called antrum
IV. Graafian follicle on getting ruptured releases primary follicle via process of ovulation
During the embryonic development stage, a couple of million gametes (egg) mother cells (oogonia) are formed within each foetal ovary. The oogonia cells enter prophase I stage of meiosis and get temporarily arrested at this stage. They are now called the primary oocytes.
Primary oocyte during the course of development gets surrounded by a layer of granulosa cells and gets transformed into primary follicles. A large number of those follicles get degenerate during the phase from birth to puberty.
Tertiary follicles on further development transformed into Graafian follicles, with a large central follicular cavity (antrum) that is filled with a fluid called liquor folliculi.
In case of no pregnancy corpus luteum gets degenerated into a white massy substance called corpus albicans which has no hormonal secretion.
The Graafian follicle is the most mature follicle which on rupturing forms a secondary oocyte via process of ovulation.