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प्रश्न
Why does menstruation occur?
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उत्तर
Menstruation is a process in which blood and mucous flow out every month through the vagina. This process occurs every month because one egg is released from the ovary every month and at the same time, the uterus (womb) prepares itself to receive the fertilised egg. Thus, the inner lining of the uterus gets thickened and is supplied with blood to nourish the embryo. If the egg does not get fertilised, then the lining of the uterus breaks down slowly and gets released in the form of blood and mucous from the vagina. It lasts for three to five days.
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संबंधित प्रश्न
How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?
State the function of Ovary.
Given here is a section of the female reproductive system of human beings.
Name the parts labelled 1 to 4
Fill in the blank:
Lower part of uterus is called _________.
Which part of the human body produces Ova?
Name the following:
The part of the female reproductive system in which fertilization occurs.
Complete the following statement by choosing the correct alternative:
Female copulatory organ ______.
State the Location:
Bartholin’s glands.
Write the functional activity of the following structure:
Fallopian tubes
Match the parts of the given figure with the correct option.
| 1 | 2 | 3 | 4 | 5 | |
| a. | Fallopian tube | Oviduct | Uterus | Cervix | Vagina |
| b. | Oviduct | Cervix | Vagina | Ovary | Vas deferens |
| c. | Ovary | Oviduct | Uterus | Vagina | Cervix |
| d. | Fallopian tube | Ovary | Cervix | Uterus | Vagina |
Which of the following statements regarding human reproduction is INCORRECT?
In 28 days human ovarian cycle, ovulation occurs on ______.
The period during adolescence when the reproductive tissues begin to mature is called ______
The fertilization of the human egg by the sperm takes place in ______
Read the following and answer from given below:
During copulation, semen is released by the penis into the vegina. The motile sperms swim rapidly, fuse with the ovum in the ampullary region, resulting in fertilization. The haploid nucleus of sperm fuses with that of the ovum to form a diploid zygote.
Select the correct sequence of various physical and chemical events that take place during fertilisation.
P. Fusion of cortical granules with the plasma membrane of secondary oocyte.
Q. Formation of fertilization cone to receive sperm.
R. Release of sperm lysin from acrosome.
S. Mixing up of chromosomes of a sperm and an ovum.
What is placenta? Mention its role during pregnancy?
In rabbits, humans and other placental mammals, fertilization occurs in ______.
Draw a neat diagram of the female reproductive system and label the parts associated with the following:
(a) production of gamete
(b) site of fertilisation
(c) site of implantation
(d) birth canal
Give reason:
Uterine lining becomes thick and spongy after fertilisation.
Which hormone facilitates contraction of fallopian tube and uterus to assist movement of sperms towards ampulla?
