When corpus luteum degenerates,
a. fsh and lh secretion start to rise as the inhibitory effects of the gonadal steroids are withdrawn
b. circulating levels of estrogen and progesterone rapidly decline.
c. the endometrium sloughs off.
d. both a and b occur
e. all of the above

The best answer to the question: When the corpus luteum degenerates:___, would be, E: All of the above.

Explanation:

The process of human female reproduction is a very complex one. But center in it is the corpus luteum, a structure that develops from a follicle in the ovaries and which will be responsible for producing estrogens and progesterones to maintain pregnany in case there is egg fertilization, or, the dismantling of everything by decaying and thus stopping the outpour of these  gonadal steroids. When fertilization occurs, the corpus luteum, by producing estrogen and progestorone, inhibits the further production of LH and FSH, and thus the entire process for a successful pregnancy takes place. But when this does not occur, LH and FSH increase again, progesterone, most especially, decreases, and as a result, the endometrium, which had been prepared for implantation, sloughs off. This is why the answer is E.

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25. anomalous, unusual, unconventional