NEET 2009
- Exam
- NEET
- Year
- 2009
- Subject
- Zoology
- Chapter
- Human Reproduction
NEET 2009 · Zoology · Human Reproduction
Which one of the following is the most likely reason of not...
Which one of the following is the most likely reason of not occuring regular menstruation cycle in females ?
Options
- AFertilization of the ovum
- BMaintenance of the hypertrophical endometrial lining
- CMaintenance of high concentration of sex-hormones in the blood stream
- DRetention of well-developed corpus luteum
Correct answer
A. Fertilization of the ovum
Step-by-step solution
If fertilization occurs and foetus is implanted in the endometrium, the trophoblast cells of the developing placenta secrete a hormone human Chorionic Gonadotrophic (hCG). This hormone like LH maintains the corpus luteum and the secretion of progesterone and estradiol by it. These two hormones check the breakdown of the endometrium of the uterus. The absence of menstrual bleeding is the earliest sign of pregnancy.