Which statement is correct about the krebs cycle? a. oxygen is a waste product of the krebs cycle. b. acetyl-coa combines with pyruvic acid to make glucose in the krebs cycle. c. the krebs cycle produces electron carriers for the electron transport chain d. in the krebs cycle, carbon dioxide is used to make glucose.

"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."