Which of the following best represents a way plants directly save people money A. They are fuel sources for underdeveloped regions.
B. They increase the values of homes.
C. They are the basis for many medicines.
D. They provide products for countries to trade.

answer; ///(b) it is composed of four protein chains and four heme groups;

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."