Final answer:
Menopause occurs due to less responsiveness of primary follicles to FSH and LH, changes in GnRH release patterns, and a decline in estrogen and progesterone levels, which lead to the end of menstruation.
Step-by-step explanation:
The onset of menopause occurs when a combination of hormonal and physiological changes take place in a woman's body. The primary factors contributing to menopause are 1) primary follicles becoming less responsive to FSH and LH, 2) changes in GnRH release patterns, and 3) a decline in estrogen and progesterone levels. All of these changes collectively contribute to the cessation of the menstrual cycle and the end of a woman's reproductive years.