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.
Without any greenhouse gases, Earth would be an icy wasteland. Greenhouse gases keep our planet livable by holding onto some of Earth's heat energy so that it doesn't all escape into space. This heat trapping is known as the greenhouse effect. ... Putting so much new CO2 into the air has made Earth warmer.
The diagram below shows a cross section of a plant leaf. How does the structure marked X contribute to the survival of the plant? It allows the intake of gases necessary for photosynth