What is the term that refers to the implantation and growth of the fetus into the walls of the fallopian tubes?

A. During labor, pressure of baby's head on cervix stimulates release of oxytocin:
This is a classic example of positive feedback-oxytocin increases uterine contractions, which increase pressure and stimulate more oxytocin release.

B. Menstrual cycle:
The menstrual cycle involves both positive and negative feedback mechanisms, but is not a pure example of positive feedback.

C. Blood glucose regulation:
This is an example of negative feedback involving insulin and glucagon.

D. Wake/sleep cycle:
This is regulated by circadian rhythms, not primarily a feedback loop of endocrine hormones.

A. Is accompanied by an increase in estrogen and progesterone secretion: Menopause is actually marked by a decrease in estrogen and progesterone due to the decline in ovarian function.

B. Is always accompanied by severe symptoms: While some women experience severe symptoms (hot flashes, mood changes), not all do. Symptoms vary greatly.

C. Usually occurs in the late 20s and early 30s: Menopause typically occurs between ages 45 and 55.

D. Is accompanied by a gradual decrease in menstrual periods: Menopause involves the gradual cessation of menstrual cycles as ovarian hormone production wanes.