Menopause marks the end of a woman's fertility and the cease of the menstrual cycle. The ovaries stop producing hormones and in humans, the menstrual cycle ceases at around 50 years of age. 

During the proliferative phase, the endometrium of the uterus becomes thicker as blood vessels become long and coiled.

Follicular atresia means degeneration of follicles. Thus, if all follicles get degenerated at the age of 45-50 years, there will be no ovulation and hence no menstruation which leads to menopause.

Menopause is a phase occurring between the age of 45 to 55 years In a woman's life when ovulation and menstruation stop.

Estrogen secreted from ovarian follicles under the influence of FSH causes the proliferation of the endometrium of the uterine wall.

Follicular atresia is the breakdown of the ovarian follicles, which consist of an oocyte surrounded by granulosa cells and internal and external theca cells. This is the reason, the female born with more than 4,00,000 eggs have a limited period between menarche and menopause.

In human females endometrium (the innermost layer of the uterus) undergoes cyclical changes every month which is known as menstruation. It starts at the age of puberty, this beginning is called menarche. Human females can only reproduce till 45 to 50 years of age. When the menstruation stops it is called menopause.

In females, the post-reproductive phase of menopause begins from the age of 45 years approximately. In this phase, the primary follicles are not available that can be developed under the effect of FSH. When follicles do not develop, ovulation cannot occur under the effect of LH. There is no corpus luteum formed, so there will be no progesterone. As there is no progesterone, the endometrium stops building up. Due to this, there are no menses occurring. Since FSH and LH are released by the pituitary gland, they would be un-used and excreted in urine.

Progesterone is a hormone which is secreted by the corpus luteum. It is responsible for the maintenance of the endometrium of the uterus. As long as the progesterone is secreted by the corpus luteum, the menses does not begin. When the corpus luteum degenerates in the absence of a fertilization event, the progesterone secretion stops and the endometrium starts to break down and menses begin. So, in order to delay the menses, intake of progesterone will be advised because it will prevent the break down of endometrium and menses will not occur.

The release of the first menstrual flow or period is called menarche. It marks the beginning of a female's reproductive life and is one of the most obvious signals of the onset of puberty. Menarche usually occurs between the age of 11-14 years. While Menopause is the condition in which menstrual cycle stops naturally in women. 

This is usually about 14 days after the first day of your last period if your cycle is around 28 days long. An egg lives for about 12-24 hours after being released. For pregnancy to happen, the egg must be fertilized by sperm within this time. Sperm can live for up to 7 days inside a woman's body.

Menstruation is a woman's monthly bleeding. It occurs so as to shed the lining of the uterus or womb.
In menstrual cycle, the uterus gets prepared for implantation and the endometrium builds up, After ovulation, if the egg released does not gets implanted in the uterus, it leads to shedding off this endometrium and its lining and this is called as menstruation,
Thus, the correct answer is option B.

The rhythmic reproductive cycle in the female primates is called as the menstrual cycle. The first menstruation begins at puberty and is called as menarche and is repeated at an average interval of about 28 / 29 days.

The reproductive cycle in the female primates is called menstrual cycle. The first menstruation begins at puberty and is called as menarche. In human females, menstruation is repeated at an interval of about 28/29 days, and the cycle of events starting from one menstruation till the next one is called as the menstrual cycle. In human beings, menstrual cycle ceases around 50 years of age; that is termed as menopause. 

The reproductive cycle in the female primates (e.g., monkeys, apes and human beings) is called as menstrual cycle. The first menstruation begins at puberty and is called as menarche. In human females, menstruation is repeated at an average interval of about 28/29 days, and the cycle of events starting from one menstruation till the next one is called as the menstrual cycle. One ovum is released (ovulation) during the middle of each menstrual cycle.

All the statements above are correct except the last one. Menstrual blood normally does not clots and flows through cervix and vagina along with inner lining of uterus. But it may clot also especially if there is blockage in cervix and free flow is obstructed. The menstrual blood contains not only blood but also tissue from the lining of the uterus. Clots are a natural way of controlling bleeding. Scientifically, it is a complicated and involved process that leads to fibrin being formed into a matrix. 
On the exposed parts of body like scraped knee, this mechanism leads to scab formation. But inside the uterus, the process results in a clot. Because blood in the uterus is mixed with many other cells and endometrial tissue, there is a difference between this clot and those seen on the skin. Whenever blood pools or is retained inside the uterus it is likely to clot. When menstrual blood and cells pass immediately outside the body, clots are less likely. As a general rule, the redder the blood is, the faster it has reached the outside. The blacker it is, the longer it took to exit the body. If the blood is accumulating faster than the body's ability to transfer it out of the uterus, clots are the result. Many women routinely have some clotting during menses. Factors that determine whether clots will occur include: the size of the uterus, the ability of the uterine myometrium (muscle) to contract, fibroids, adenomyosis, the diameter of the cervical canal through which the blood must flow, any obstruction to the outflow of menstrual products such as polyps, adhesions, etc.

Menopause is the cessation of the monthly cycle wherein ovaries do not respond to gonadotropic hormones produced by the anterior pituitary and do not secrete oestrogens and progesterone. It marks the end of a reproductive phase of the human female. Deposition of subcutaneous fat, the presence of pubic hair and development of mammary glands are secondary sexual characters in human females. The correct answer is A.

• Menstruation is a woman's monthly bleeding. It occurs so as to shed the lining of the uterus or womb. 
• In the menstrual cycle, the uterus gets prepared for implantation and the endometrium builds up. 
• After ovulation, if the egg released after fertilization, does not get implanted in the uterus, it leads to shedding off this endometrium and its lining and mucus and this is called menstruation. 

The level of progesterone hormone decreases after the regression of corpus luteum, causes the uterus to shed its lining and egg in a process termed as menstruation. 

• Menstruation is a woman's monthly bleeding. It occurs so as to shed the lining of the uterus or womb. In the menstrual cycle, the uterus gets prepared for implantation and the endometrium builds up.
•  After ovulation, if the released egg does not get implanted in the uterus, it leads to shedding off the endometrium and its lining and this is called menstruation and it generally lasts for 3-4 days.

• Menstruation is a woman's monthly bleeding. When the egg is released by the ovary, the body prepares for fertilization but building up the uterine layer and other hormonal changes. 
• However, if the egg is not fertilized, the body sheds this lining of the uterus and mucus and this is called menstrual blood and it passes from the uterus through the cervix and passes out the body through the vagina.

The mature egg is released from the ovary and pushed down the fallopian tube for it to fertilize. If no fertilization takes place, the egg degenerates and is shed from the body along with the uterine lining as well as the blood, which happens during the menstruation.
Thus, the correct answer is option B.

Menarche is the first menstrual cycle in female humans.
Menopause is the end of menstrual cycle.

Menopause is the time in a woman's life when her menstrual periods stop and she is no longer able to have children (i.e., no longer fertile), which generally happens after the age of 40-45 years.
Menstruation is the woman's monthly cycle, menarche is the first menstrual period and ageing is the general phenomenon of growing old.

• The first menstrual cycle begins at puberty but is not called menopause, instead it is called menarche. 
• Menarche is the first menstrual flow/discharge in female humans. Menopause marks the end of the menstrual cycle,

Once a girl starts menstruation, her body needs more iron to make up the amount of iron they lose in their menstrual cycle. During menstruation, blood flows out from the body after a fixed interval. As we know haemoglobin is composed of a protein called globulin, four heme groups, each associated with an iron atom. In the absence of iron the person becomes anemic. So, avoid this condition in females, it is necessary to take more iron in females.

14th day of menstrual cycle will be ovulation day. Thus she will release ovum on 14th March. Next menstrual cycle will trigger on 29th March, that is after exact 28 days of previous menstrual cycle. Thus, the correct answer is option B.

The corpus luteum secretes large amounts of progesterone which is essential for maintenance of the endometrium (wall of the uterus) . Such an endometrium is necessary for implantation of the fertilized ovum. In the absence of fertilization, the corpus luteum degenerates resulting in decline in the progesterone level. This causes disintegration of the endometrium leading to menstruation, making a new cycle. 

Premenstrual syndrome (PMS) is a group of symptoms linked to the menstrual cycle in women. PMS symptoms start 1-2 days before the period and some of these symptoms include acne, swollen or tender breasts, trouble sleeping, upset stomach, bloating, constipation or diarrhoea, anxiety, depression etc.
Thus, the correct answer is option A.

Progesterone is the hormone which is released by the corpus luteum and the placenta. The hormone is known as the pregnancy hormone which helps in the maintenance of the cell lining of the endometrium. When the released egg is not fertilised, then the level of progesterone decreases as the corpus luteum degenerates. The low level of progesterone results in shedding of the cells from the uterine wall causing menstruation. 

Females of most vertebrate species exhibit recurring periods of heightened sexual activity in which they are sexually attractive, proceptive and receptive to the males. In mammalian females (except humans, old world monkeys and apes) this periodic sex appeal is referred to as estrous or heat i.e., ready to accept a male and to mate. One or more estrous may occur during the breeding of a species. Prior to ovulation, the endometrium (uterine wall) thickens, in preparation for holding the fertilised ova. As the proliferation of uterine tissue reaches its peak, receptivity is highest. 

After the age of 45, the number of ovarian follicles decreases and the ovaries become less responsive to luteinizing hormone and follicle-stimulating hormone. Hence the ovaries stop producing estrogen and progesterone. So the menstrual cycle stops and reproductive capacity is arrested. Menopause marks the end of reproductive phase. 

The complete end of the menstrual cycle in females is marked by menopause. Menopause can occur in your 40s or 50s. Menopause is a natural biological process. Although it also ends fertility, you can stay healthy, vital and sexual.

Menstruation is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. Up to 80% of women report having some symptoms prior to menstruation. Common symptoms include acne, tender breasts, bloating, feeling tired, irritability, and mood changes. These symptoms interfere with normal life, and therefore qualify as premenstrual syndrome, in 20 to 30% of women. In 3 to 8%, symptoms are severe. 

The physical symptoms such as hot flashes and emotional symptoms of menopause may disrupt your sleep, lower your energy or for some women trigger anxiety or feelings of sadness and loss. Therefore, (c) is the correct answer.

The menstrual cycle is the reproductive cycle which takes place in the females in every 28 days after puberty. The ovulation is the release of the egg or the female gamete which takes place on the 14$^{th}$ day of the cycle. There is only one egg produced and released every month. The process of menstruation is the bleeding phase which takes place every from for about 5 days.

Ovulation is the process of releasing the matured egg or ovum.
Puberty is the process of physical changes whereby the child's body matures into an adult body capable of sexual reproduction.
The cessation of the woman's menstrual cycle and hence the end of reproductive ability is called as menopause. Menopause occurs due to the natural cessation of the estradiol and progesterone production by the ovaries over a period of years. This is the part of the normal aging process.
The process of becoming mature is maturation.
Thus, the correct answer is (C), 'Menopause'.

ovulation is the process of the release of a mature egg during menstruation cycle. In a typical 28 human ovarian cycle ovulation occurs on day 14.

The last menstrual cycle or cessation of the menstrual cycle in women at the age of $45-50$ years is known as menopause. It marks the end of reproductive life of women. 

• The first menstrual cycle that occurs during puberty at the age of $11-14$ years is known as menarche.
• The last menstrual cycle or cessation of the menstrual cycle at the age of $45-50$ years is known as menopause. 
• Menarche marks the beginning of reproductive life and menopause marks the end of the reproductive cycle.

Ovaries in woman stop their action at an early age by 40 for about 2%. Ovarian failure occurs at an average age of menopause is 50 years old.

The gamete formation in females is a cyclic activity that takes about 28/29 days and involves changes in the structure and function of the entire reproductive system. It is called menstrual cycle.

Just after the menstrual phase, the proliferative phase starts that shows an increase in the level of the FSH or follicular stimulating hormone. This leads to the regeneration of the endometrium lining. The regeneration takes around 5 to 10 days. On the 14$^{th}$ day, the ovulation takes place.

Menstruation is triggered by reduced levels of the hormones estrogen and progesterone in a female's body at the end of the previous menstrual cycle. This decline in hormone levels is due to the absence of a fertilized egg implanting on the walls of the endometrium.

Menstruation starts at puberty which is known as menarche. It is the shredding of endometrial lining, ovum and some blood vessels. It ends at the age of 45 to 50 which is known as menopause. It is a cyclic process which happens every month. It includes the menstrual phase, the follicular phase, the ovulatory phase, and the luteal phase. Ovulatory phase happens because of a sudden release of LH hormone.

After ovulation, the pituitary hormones FSH and LH cause the remaining parts of the dominant follicle to transform into the corpus luteum, which produces progesterone. The increased progesterone in the adrenals starts to induce the production of estrogen. The hormones produced by the corpus luteum also suppress production of the FSH and LH that the corpus luteum needs to maintain itself. Consequently, the level of FSH and LH fall quickly over time, and the corpus luteum subsequently atrophies. Falling levels of progesterone trigger menstruation and the beginning of the next cycle.

• The menstrual cycle is a monthly cycle in which the primate females ovulate once in a month.
• Menstruation is important because it prepares the body for the fertilization and is a key process in reproduction.
• The cycle occurs in humans, chimpanzees and Orangutans, gorillas and monkeys.
• Other mammals have a similar cycle which is known as the oestrous cycle.

The functional layer of the human endometrium is a highly regenerative tissue undergoing monthly cycles of growth, differentiation, and shedding during a woman's reproductive years. Fluctuating levels of circulating estrogen and progesterone orchestrate this dramatic remodeling of human endometrium.

If fertilization does not occur, progesterone inhibits LH from pituitary.

If fertilization does not occur in the uterus, the corpus luteum will involute and there will be a drop in the hormone levels, which will cause the uterus to shed its lining and egg in the process called menstruation, where there is blood and uterine secretions are removed through the vagina.
Therefore, the correct answer is option C.

Menarche is the first occurrence of menstruation and marks the beginning of the reproductive period.
Menopause is the end of menstruation and marks the end of the reproductive period of women.
Therefore, the correct answer is option A.

Menstrual cycle is rhythmic reproductive cycle in which the endometrium wall of uterus forms placenta. Placenta provides nourishment to the developing fetus if implantation occurs. If pregnancy does not occur, this endometrial lining is shred off, known as menstruation. So, this endometrium thickening is not permanent.
Thus, the correct answer is option B.

Puberty is the stage at which physical changes occurs through which a child's body matures into an adult body to enable fertilization.
Pubertal changes in girls is secondary sexual characteristics which involves development of breast, pubic hair, changes in vagina, uterus and ovaries, menstruation, development of acne due to hormonal changes.
Thus, the correct answer is option D.

Ovulation is the process when a mature egg is released from the ovary. Then the egg is pushed down the Fallopian tube and is available to be fertilized. In females, ovulation continues after the age of 45-50 after which eggs are not released from the ovary and there is menopause.
Thus, the correct answer is option (A), '45-50'.

• Menstruation also is known as a monthly bleeding cycle that occurs in a female. During the period of 21-28 days oviduct, a part of the female reproductive system produces an egg in the process called ovulation. In this duration, the uterus prepares itself by increasing blood supply with arteries and veins, building a placenta to support the embryo if the egg gets fertilized by a sperm. If the egg is not fertilized the uterus starts contractions to break down the placenta. This process of rupturing the placenta from the uterus wall goes on for 3-5 days and is called menstruation. 
  
• Luteinization is an early step in the formation of griffin follicles, an early stage of a mature ovum.
• Oogenesis is a complete process by which egg/ovum is formed.
• Estrogeniztion is the production of thick pale fluid produced by the action of estrogen during puberty in females.

If the fertilization occurs and the foetus is implanted in the endometrium, the trophoblastic cells of the developing placenta and secrete the hormone which is the human chorionic gonadotropin. This hormone, like LH, maintain the Corpus luteum and the secretion of progesterone and oestrogen by it. These two check the breakdown of the endometrium of the uterus. The absence of menstrual bleeding is the earliest sign of pregnancy. Fertilization is diploid condition and equatorial division is complete only fertilization occurs.

Polar bodies are formed each monthe after attaining puberty. Hence, total years of polar bodies formation are equal to the difference between the age of puberty till date. 

If fertilized egg is not implanted into the uterus after the release of the matured egg, the corpus luteum degenerates and the levels of estrogen and progesterone decrease. The decrease in the level of progesterone causes the endometrium to degenerate initiating the menstrual cycle. This causes the hypothalamus to stimulate the release of GnRH, which in turn causes the release of LH and FSH from the anterior pituitary. The rising level of LH and FSH causes the growth of follicles on the ovarian surface, preparing for ovulation and thus beginning the ovarian cycle. So, the correct option is 'hypothalamus stimulates the anterior pituitary to increase its output of FSH and LH'.

Menopause is the time when menstrual cycles permanently cease. Symptoms of menopause include irregular periods, hot flashes, vaginal dryness, mood swings. During natural menopause, estrogen and progesterone levels in blood decreases. However, the levels of FSH and LH in blood increases during this time. High levels of FSH is an indicator of perimenopause period.

Puberty is the period of growth that bridges childhood to adulthood and results in physical and several maturities as well as the capacity for reproduction. Over half of pubertal timing is considered heritable.

Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers. During the menstrual cycle, when an egg is released from the ovary at ovulation (approximately day 14), the remnants of the ovarian follicle that enclosed the developing egg form a structure called as the corpus luteum. This releases progesterone and, to a lesser extent, oestradiol. The progesterone prepares the body for pregnancy in the event that the released egg is fertilised. If the egg is not fertilised, the corpus luteum breaks down, the production of progesterone falls and a new menstrual cycle begins. Estrogen or oestrogen is the primary female sex hormone and is responsible for development and regulation of the female reproductive system and secondary sex characteristics. Follicle stimulating hormone is produced by the pituitary gland. It regulates the functions of both the ovaries and testes. Lack or insufficiency of it can cause infertility or subfertility both in men and women. In females, an acute rise of LH ("LH surge") triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with FSH. 

The clot is made up of blood cells, fibrins and endometrial tissues. Since the blood passes from uterus quickly then there is no time for anticoagulants to act. So, clots cannot be formed easily.