Human Reproduction Ques 20
20. Which one of the following is the most likely root cause why menstruation is not taking place in regularly cycling human female? [2009]
(a) maintenance of the hypertrophied endometrial lining
(b) maintenance of high concentration of sex hormones in the blood stream
(c) retention of well -developed corpus luteum
(d) fertilisation of the ovum
Show Answer
Answer : d
Hints & Solutions
(d) Fertilization of ovum is the most likely root cause of when menstruation is not taking place in regularly cycling human female. In order for fertilization to occur, one of these sperm must attach itself to the ovum and penetrate its outer surface. The fertilized ovum will then continue travelling down the fallopian tube, taking several days until it reaches the uterus. When it arrives, it attaches itself to the lining of the uterus and continues to grow. If the ovum is not fertilized it will die and the progesterone and oestrogen hormone levels will drop. Without these hormones the prepared uterus lining breaks up and is released through the vagina. This is known as a ‘period’. Menstruation is the biological process which involves bleeding from the vagina that happens about once a month, as a normal part of the menstrual cycle. It is also known as having a period. During this cycle, hormones make the lining of the uterus become thicker, getting ready in case of pregnancy. Hormones also cause an egg to be released from an ovary, which is known as ovulation. In case, fertilisation does not occur the lining of the uterus falls away and, along with some blood, flows out through the vagina.Diem nihi, vicerum, catiu quem mandic re norus iae aciamquem porionv ocupica; et
BETA
