Question

The graph shows the changing levels of hormones during menstruation and ovulation.

In general, what happens to the hormone levels between days 21 and 27, just prior to menstruation if the egg was not fertilized?
Hormone levels generally decrease.
Hormone levels generally rise.
Hormone levels remain the same.
Hormone levels go in two different directions

Answer 1

Hormone levels generally decrease.

If the egg isn't fertilized, the corpus luteum degenerates and progesterone and estrogen fall sharply (with LH/FSH low but beginning to rise only as negative feedback ends), triggering menstruation.