Answer: Shedding of the endometrium lining when pregnancy does not occur.
- A Release of a mature egg from the ovarian follicle at the midpoint of the cycle
- B Shedding of the endometrium lining when pregnancy does not occur
- C Fertilization of the egg by sperm somewhere within the fallopian tube
- D Implantation of the developing blastocyst into the thickened uterine wall
Correct answer: B. Shedding of the endometrium lining when pregnancy does not occur
Explanation: Menstruation (period) is the shedding of the endometrium (uterine lining) when pregnancy does not occur. It happens when progesterone and estrogen levels fall after corpus luteum degeneration. Lasts about 3-5 days.
The human male reproductive system: sperm formed in the testis mature in the epididymis and travel via the vas deferens, mixing with secretions of the seminal vesicle, prostate and bulbourethral glands. Image: Wumingbai, CC BY-SA 4.0, via Wikimedia Commons.
Concept context
Male and female reproductive systems, gametogenesis, fertilization, implantation, pregnancy, and reproductive health.