[Campbell Biology P.1082] If pregnancy does not occur after the luteal phase, what is the seq... | Practice Question
If pregnancy does not occur after the luteal phase, what is the sequence of events that follows?
A: The corpus luteum disintegrates, leading to a decline in estradiol and progesterone, which then liberates the hypothalamus and pituitary from negative feedback.
B: The corpus luteum continues to secrete high levels of progesterone, preventing the growth of new follicles.
C: High levels of gonadotropins are maintained, stimulating new follicle growth directly.
D: The endometrium continues to thicken, preparing for a potential future pregnancy.
Explanation
The text states: 'If pregnancy does not occur, the low gonadotropin concentration at the end of the luteal phase cause the corpus luteum to disintegrate, triggering a sharp decline in estradiol and progesterone concentrations. This decline liberates the hypothalamus and pituitary from negative feedback.'