female reproductive system undergoes some changes and those changes repeat at interval of every 28-30 days. this repetative changes are called menstrual cycle. it is natural process, controlled by four hormones. those four hormones follicle stimulating hormone,luteinizing hormone, estrogen and progesterone. one of several follicle in ovary starts to develop along with oocyte present in it,under effect of follicle stimulating hormone. developing follicle secrets estrogen. endometrium of uterus starts to regenerate under effect of estrogen. it bursts under effect of luteinizing hormone and oocyte is released. this is ovulation. remaining tissues of burst follicle forms corpus luteum. corpus luteum starts to secrets progesterone. endometrial glands secrets their secretion under effect of progesterone. such endometrium is ready for implantation of embryo.
Reductionism is a philosophical theory used to explain different phenomena from simpler phenomena. This idea represents a useful methodology to understand complex processes, and it is widely used in molecular biology and genetics research fields