Answer to Question 1
Answer: The rodent estrous cycle is four days in length and involves the secretion of estradiol followed by progesterone. Exposure of a female mouse to the odor of other female mice can slow their estrous cycles (Lee-Boot effect), while exposure to a male mouse can restart the cycle (Whitten effect). Moreover, the urine from a male mouse can speed up the onset of puberty (Vandenbergh effect) or can cause a pregnant female to abort a fetus fathered by another male mouse (Bruce effect). These effects require an intact vomeronasal organ.
Answer to Question 2
Answer: The internal and external genitalia will develop into a female form in the absence of any hormone stimulation. In order to develop the external male genitals, dihydrotestosterone
must be present. Because both male and female precursor tissues exist for the internal
reproductive structures, the female system (Mllerian) must be inhibited by anti-Mllerian hormone, and the male Wolffian system must be stimulated by the presence of androgens.
A parasite life cycle.
Estrogen and Progesterone Levels During Menstrual Cycle
Effects of Insulin and Glucagon on Glucose and Glycogen
Effects of viruses on their host cells.
Melting ice and snow have far-reaching effects
The Hydrologic Cycle