The shedding of the endometrium occurs during resulting from a decrease in

The shedding of the endometrium occurs during menstruation resulting from a decrease in progesterone and estrogen.

Explanation:

The endometrium is la innermost tissue of the uterus, and its function is to keep the myometrium separated. During the menstrual cycle, it becomes a tissue rich in blood vessels with a bigger thickness than its usual. Preparing itself to receive an egg to be funded and develop a fetus. However, if the egg is not fecundated it sheds and releases all the blood, proteins, and substances it gathered to receive a fecundated egg for its development. This process requires hormones, proteins, and other blood cells to repair the damage inside the uterus. Including progesterone and estrogen.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands