Question

feedback scenario #2: in females, the levels of the hormone estrogen in the blood peak just prior to ovulation, the release of an egg from the ovary. a rise in estrogen causes the release of a hormone from the brain (luteinizing hormone), which leads to additional increases in estrogen levels. table 2: blood estrogen levels in the days before ovulation

time (days)	0	1	2	3	4	5	6

1. the data show rising estrogen levels before ovulation, which trigger ovulation. which of the following scenarios is most similar to this type of feedback?

a. during childbirth, contractions cause the release of oxytocin, which increases contractions normal.
b. after eating, rising blood glucose causes insulin release, which lowers glucose levels back to normal.
c. when body temperature rises, sweating helps cool the body until temperature returns to normal.
d. when oxygen levels drop, breathing rate increases until oxygen levels return to normal.
on the next page, construct line graphs from the data provided in scenario 1 and scenario 2.

Explanation:

The estrogen - ovulation scenario is a positive feedback loop (rising estrogen triggers more estrogen release via LH, leading to ovulation). Option a: Childbirth - contractions trigger oxytocin release, which increases contractions (positive feedback, similar to estrogen - ovulation). Option b: Eating - rising glucose triggers insulin, which lowers glucose (negative feedback, different). Option c: Body temperature - rising temp triggers sweating to lower temp (negative feedback, different). Option d: Oxygen - low oxygen triggers increased breathing to raise oxygen (negative feedback, different). So the most similar is option a.

Answer:

a. During childbirth, contractions cause the release of oxytocin, which increases contractions normal.