Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers.
I've been following various people's posts about the GRE for 10 months now. Some people don't study at all for the GRE, some study for a weekend, the average is about 2 to 3 months, and some study for a year or more.
You can take the GRE exam on paper or on a computer. GRE testing time will vary depending on which version of the test you take and the potential presence of unscored research sections, but plan to set aside at least three hours.