In a young female of reproductive age with regular menstrual cycle of 28 days, ovulation occurs at around 14th day of periods. When is the first polar body extruded?: (A) 12 hrs prior to ovulation, (B) Accompanied by ovulation, (C) 48hrs after the ovulation, (D) At the time of ovulation
Answer is A. Primary oocyte remain in prophase of meiosis I until primodial follicle grow to form primary follicle which grows to form secondary/graffian follicle. The secondary follicle enters preovulatory stage 36 hrs before ovulation when LH surge occurs resulting in completion of meiosis -I and formation of secondary oocyte and 1st polar body 12hrs prior to ovulation(LH peak occurs).