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The follicle that released the ovum suffers the action of LH and is transformed into the corpus luteum. The corpus luteum is very important because it secretes estrogen and progesterone.

These hormones prepare the uterine mucosa, also known as endometrium, for nidation (implantation of the zygote in the uterine wall) and embryonic development since they stimulate the thickening of the mucous tissue, increase its vascularity and make the appearing of uterine glycogen-producing glands.

The hormones that promote the release of the ovum from the follicle are FSH and LH, hormones found in maximum blood concentration around the 14th day of the cycle. The release of the female gamete from the ovary is called ovulation. Ovulation happens at (around) the 14th day of the menstrual cycle.

The IUD (intrauterine device) is a piece of plastic coated with copper that is inserted within the uterus by a doctor.

Copper is then gradually released (IUD may last 5 to 10 years) and since it has a spermicidal action sperm cells are destroyed before fecundation. Besides this mechanism the movement of the IUD inside the uterus causes slight endometrial inflammation that helps to prevent nidation. 

One can imagine a cycle like an analog clock at which at 0 o’clock is the beginning and the end of the menstrual cycle and that 6 o’clock corresponds to the 14h day of the cycle.

At 0 o’clock the menses and so the menstrual cycle begins and FSH blood level begins to increase. Around 2 o’clock the maturing follicles under FSH action are already secreting estrogen and the endometrium is thickening. Around 3 o’clock estrogen is intensely stimulating the increase of LH blood level. At 6 o’clock (the 14th day) LH is at its maximum concentration and FSH also at high levels to promote ovulation,

LH then stimulates the formation of the corpus luteum. Around 7 o’clock the corpus luteum is already secreting a great amount of estrogen and progesterone and the endometrium thickens even more, concomitant lowering of FSH and LH occurs with the increasing of the ovarian hormones. Around 11 o’clock the reduced LH and FSH levels make the corpus luteum turn into the corpus albicans, the production of estrogen and progesterone ceases and the endometrium regresses. At 0 o’clock again (28th day) the endometrium desquamates and a new menstrual cycle begins.

Vasectomy is the most common method of surgical sterilization in men. In vasectomy the vas deferens inside the scrotum are sectioned and closed at a section which will forbid the sperm cells to follow to the ejaculatory duct but still allowing the release of seminal fluid during ejaculation.

Surgical sterilization of women is often done by bilateral tubal ligation. With tubal ligation the ovum does not pass to the uterus so the sperm cells cannot reach it.

Parthenogenesis is the reproduction or formation of a new individual from the egg cell but without fecundation by the male gamete. According to the species, individuals born by parthenogenesis may be male or female, or of any sex.

In bees the drone (the single male bee) is haploid and born by parthenogenesis while the females (queen and workers) are diploid.

A. True In its absence spermatogenesis is depressed. 

B. True This controls secretion of testosterone. 

C. True This also is required by the germinal epithelium. 

D. False Testicular temperature should be maintained around 32^oC. 

E. False The normal value is around 10⁸/ml.

If fecundation does not occur approximately 24 hours after ovulation the released ovum often dies.

Laboratory tests to detect pregnancy commonly test for human chorionic gonadotropin (HCG) concentration in blood or urine samples. If the level of this hormone is abnormally high, pregnancy is likely.

The placenta besides being the organ through which the exchange of substances between the mother and the fetus is done also has the function of secreting estrogen and progesterone to keep a high level of these hormones during pregnancy. (The placenta still secretes other hormones like human placental lactogen, that act similarly to the hypophyseal hormones that regulate reproduction, and HCG, human chorionic gonadotropin.)

The endocrine glands that secrete hormones involved in the menstrual cycle are the hypophysis (pituitary) and the ovaries. 

The hormones from adenohypophysis are FSH (follicle-stimulating hormone) and LH (luteinizing hormone) and the hormones from the ovaries are estrogen and progesterone. 

In most vertebrate species with internal fecundation the females have reproductive cycles with fertile periods. During this period the female secretes pheromones (odoriferous substances that attract the male of the species) from the skin and mucosae. The presence of the male individual and his pheromones also stimulates the release of pheromones by the female. (Many animals also use pheromones for territorial demarcation and for signal transmission between individuals about the location of dangers and food.)

A. True This negative feedback keeps blood testosterone constant. 

B. True Sexual precocity can cause short stature. 

C. False Testosterone is anabolic and leads to skeletal muscle hypertrophy. 

D. False Scalp hair tends to recede. 

E. True This is a male secondary sexual characteristic.

A. True Adrenal androgens may lead to precocious puberty. 

B. True Sex hormones cause closure of the epiphyses. 

C. True If it secretes a gonadotropin-releasing hormone. 

D. True If gonadotropins are produced. 

E. True There is a wide scatter in the normal distribution of the age of onset of puberty.

In males the sexual activity is regulated by the endocrine glands hypophysis (pituitary), adrenals and gonads (testicles).

The FSH (follicle-stimulating hormone) secreted by the adenohypophysis acts upon the testicles stimulating the spermatogenesis. The LH (luteinizing hormone), another adenohypophyseal hormone, stimulates the production of testosterone by the testicles too. Testosterone, whose production intensifies after the beginning of puberty, acts in several organs of the body and it is responsible for the appearing of the male secondary sex characteristics (beard, body hair, deep voice, increase of the muscle and osseous mass, maturation of genitalia, etc.) Testosterone also stimulates spermatogenesis.

The functioning of the hypophysis is altered during pregnancy. Since estrogen and progesterone levels remain elevated during the gestational period the production of GnRH (gonadotropin-releasing hormone) from the hypothalamus is inhibited. The lack of GnRH thus inhibits the secretion of FSH and LH from the hypophysis and a new menstrual cycle does not begin.

If pregnancy does not occur the lowering of estrogen and progesterone levels stimulates the production of GnRH by the hypothalamus. This hormone then hastens the adenohypophyseal secretion of FHS and LH that in their turn stimulate the maturation of follicles and the beginning of a new menstrual cycle.

Although this is not a rule, to be effective fecundation in general must occur within about 24 hours after ovulation (that occurs around the 14th day of the menstrual cycle). Fecundation may occur even if copulation took place up to 3 days before ovulation since the male gametes remain viable for about 72 hours within the female reproductive system.

The fertile period of the women however is considered the period from 7 days before ovulation to 7 days after ovulation.

A. True Due partly to depletion of iron stores. 

B. True Due to flabby uterine and abdominal wall muscles. 

C. True There have been more opportunities for sensitization. 

D. True Again due to deteriorating uterine function. 

E. True Due to pelvic damage.

A. True The sperms should be motile for at least one hour. 

B. True This indicates a serious defect in sperm formation. 

C. False This is the normal value. 

D. False The count must be below 10–20 per cent to cause infertility. 

E. True This neuropathy can affect the sexual reflexes.

By convention the menstrual cycle begins at the day that menses begins. (Menses is the endometrial hemorrhage excreted through the vaginal canal.) At these days the hormones FSH, LH,estrogens and progesterone are in low concentration.

A. True Gonadal hormones are essential for their development. 

B. False Testosterone promotes secondary sexual characteristics even if the germ cells cannot develop. 

C. False They are delayed but appear eventually. 

D. False In most cases they develop. 

E. True These are required to stimulate the gonads to produce the essential sex hormones.

The meiosis that forms female gametes begins in the cells of the ovarian follicles before birth. After the beginning of puberty, under hormonal stimuli, during each menstrual cycle one of the cells is released on the surface of the ovary and meiosis resumes. The meiotic process is only concluded however if fecundation happens.

Nidation is the implantantion of the embryo in the uterus. Nidation occurs around the 7th day after fecundation, i.e., 7 to 8 days after ovulation (obviously, it occurs only if fecundation also occurs). Since it occurs in the luteal phase the progesterone level is high and the endometrium is in its best condition to receive the embryo.

The normal duration of the menstrual cycle is 28 days but it can vary among different women or in different cycles of the same woman.

In the calendar contraceptive method the date n-14 (n minus 14) is taken considering n the number of days of the normal menstrual cycle of the woman (generally n=28). The safety margin +3 or –3 refers to the days around n-14 that intercourse should be avoided to prevent pregnancy. (This method is not exempt from failures. A doctor must always be consulted before relying on any contraceptive method.)

The excess of assets over liabilities in non-trading concern is treated as Capital fund

A. True Uterine contraction is less effective in stopping bleeding. 

B. True Again, due to deteriorating uterine function with age.

C. False It is less; Caesarean section is more often needed. 

D. True Down’s syndrome is one example of the genetic problems. 

E. True Fetal abnormalities may be an important cause of this.

A. False It falls from around 170–200 g/litre to around 110 g/litre. 

B. True The placenta contains about half as much blood as the fetus; some can be transferred by uterine contraction. 

C. False Its weight should be doubled at this stage and trebled at one year. 

D. True It can tolerate about 25 per cent of the normal adult fasting level. 

E. True Fetal tissues are adapted to survive moderate hypoxia.

A. False The pale grey colour suggests circulatory failure. 

B. False This suggests recovery from vagal slowing. 

C. False These are a good sign.

D. True This suggests severe hypoxia. 

E. True This indicates depressed reflexes.

A. False The immature ova are formed before birth and no more are developed after birth. 

B. True Because of their secretion of oestrogen and progesterone. 

C. False Identical twins are derived from a single ovum. 

D. True Follicles disappear and are replaced by fibrous tissue. 

E. False Withdrawal of ovarian hormones leads to vasoconstriction.

A. False Its formation starts around the 35th week.

B. True Fetal breathing movements wash it into this fluid. 

C. False It increases the work of inspiration. 

D. False Without surfactant the surface tension forces are great; these forces must be overcome during inspiration. 

E. False The lungs are not used for gas exchange before birth; lack of surfactant causes poor oxygenation in the neonate.

A. True The endometrium is in the secretory phase of the cycle. 

B. True It is very low on the seventh day. 

C. False Oestrogen remains high in the second half of the cycle. 

D. False The maximum is around the 14th day. 

E. True Conditions are optimal for implantation.

A. False It varies widely but averages about 30 ml (one ounce). 

B. True This occurs in the first half of the cycle. 

C. True This mucus ‘cascade’ may facilitate sperm passage. 

D. False The LH surge precedes and initiates ovulation. 

E. True Metabolic rate is raised by progesterone.

A. False This is a normal derivative of progesterone which dominates the second half of the cycle. 

B. True Normally there is a rise in the second half of the cycle. 

C. False This is a sign of ovulation (mittelschmerz). 

D. True Progesterone would normally prevent this effect (‘ferning’ due to salt crystals) in the second half of the cycle. 

E. False Proliferating glands are normally present at this stage.

A. False He develops into a normal male. 

B. True The gonads fail to develop (Turner’s syndrome). 

C. False Abnormalities do not result. 

D. False He develops as a male with abnormal testes and a high risk of mental retardation (Klinefelter’s syndrome). 

E. True Haemophilia is an X-linked recessive condition.

A. False The normal volume is 2–5 ml. 

B. False These contribute only about 20 per cent of volume. 

C. True Seminal vesicles contribute about 60 per cent of seminal volume (prostate 20 per cent). 

D. True These help to neutralize acidic vaginal fluids.

E. True Derived from seminal vesicles, prostaglandins may induce contractile activity in the female genital tract.

A. Option 2 Total mass of all fetuses. Despite each fetus being small for its age, the total mass is exceptionally large, exaggerating the likelihood of labour before completion of the usual nine months of gestation. 

B. Option 6 Assisted reproduction. Insertion of early embryos into the uterus as a means of treating infertility is a common cause of multiple birth; such embryos are at increased risk of abortion, so it is usual to insert several. 

C. Option 1 Individual fetal mass. Each fetus of a multiple set is smaller than average at the time of labour, so is less likely to be hindered by a relatively small birth canal. 

D. Option 3 Fetal prematurity. The more premature the fetus, the less mature is its liver, and the less able is it to conjugate the bilirubin load after birth; more seriously, it is also much more likely not to have developed the capacity to produce adequate surfactant to reduce the otherwise punishing effect of surface tension forces in the newborn lung. 

E. Option 7 Perinatal mortality. This term refers to the risk of death in late pregnancy and early infancy; it mounts dramatically with the number of fetuses because of the combined effects of placental inadequacy, prematurity, and the problems of dealing with multiple infants at one delivery

A. False They secrete testosterone into the circulation.

B. False This hormone is produced by the seminiferous tubules. 

C. True LH is the interstitial cell-stimulating hormone in the male. 

D. True Gonadotropin releasing hormone from the hypothalamus is needed for LH secretion. 

E. False Undescended testes can secrete testosterone.

A. Option 3 Inhibin. This hormone (like many others) exists in several forms sometimes referred to as the inhibins; in the testis it is formed by Sertoli cells which nurture spermatozoa, so are a marker for spermatogenesis, completing the feedback loop. 

B. Option 7 Testosterone. Among its widespread effects, testosterone, which is formed by interstitial cells of the testis, is responsible for spermatogenesis in the seminiferous tubules. 

C. Option 2 Gonadotrophin-releasing hormone. This key hormone is required for the release of follicle-stimulating and luteinizing hormones in both sexes, so is responsible for all sexual activity; control by the hypothalamus allows the complicated control which is different in the two sexes, so that, while male sexual activity shows no regular fluctuation, female sexual activity follows the monthly cycle, which can be modified by nutritional and psychological factors. 

D. Option 6 Progesterone. As implied by its name, this hormone is particularly associated with gestation; in the second half of the cycle it stimulates development in the endometrium which favours implantation of a fertilized ovum. 

E. Option 4 Luteinizing hormone. A surge of this hormone is the precursor of ovulation and it also acts in the testis, giving it the secondary name of interstitial cell-stimulating hormone; note that, as in the body generally, hormones are either peptide or steroid based; in the reproductive system the peptides tend to be common to male and female, whereas the steroids make the difference.

A. Option 5 40–45 years. This is the last epoch with a moderate fertility; by this time the primordial ova are four decades old. 

B. Option 3 20–25 years. In both sexes most physical characteristics are around the optimal. 

C. Option 6 50–55 years. A minute number of conceptions take place around the age of 50; nearly all women have reached the menopause with its surge of gonadotrophins directed at the senescent gonads. 

D. Option 1 10–15 years. Changes in fat and hair distribution, the onset of menstruation (menarche) and the adolescent growth spurt usually begin in this epoch. 

E. Option 7 60–65 years. Some 15 years after the menopause these changes are associated with withdrawal of oestrogens and progesterone; many women take hormonal replacement therapy during this period; it relieves hot flushes and other symptoms which may be related to the surge in gonadotrophins; some protection against coronary artery disease and osteoporosis can be balanced against adverse long-term effects.

A. Option 4 Month eight. In the last trimester (3-month period) of pregnancy, the hormones sustaining pregnancy are having their maximal effect; the maximal level of chorionic gonadotrophin occurs in the first trimester when it is maintaining the corpus luteum. 

B. Option 3 Month five. The middle trimester tends to have the least discomfort; morning sickness has usually subsided and the physical effects of a relatively huge uterus in the last trimester are not yet marked. 

C. Option 1 Month one. The gonadotrophin rises rapidly to produce the corpus luteum essential in the first trimester, and the corpus luteum rapidly increases its activity to initiate the major changes of pregnancy via oestradiol and progesterone. 

D. Option 2 Month two. The middle of the first trimester is the mirror image of the last trimester in terms of these hormones. 

E. Option 4 Month eight. Regurgitation is favoured by relaxation of the lower oesophageal sphincter, particularly by progesterone and by the concomitant surge in uterine size and intra-abdominal pressure; both of these effects subside dramatically on delivery of the baby, and so does the heartburn.

A. Option 3 Seminiferous tubules. This is where the spermatozoa originate and begin their development. 

B. Option 1 Leydig cells. These are the interstitial cells between the seminiferous tubules. 

C. Option 4 Epididymis. This is the main storage and maturation site. 

D. Option 5 Seminal vesicles. These contribute about two-thirds of the ejaculate volume; the alkalinity protects the sperm against vaginal acidity and the fructose is a source of energy. 

E. Option 7 Vas deferens. This transports the spermatozoa under the influence of sympathetic stimulation of the smooth muscle in its wall.

The Correct Answer is Black Soil.

Black Soil

• The colour of the black soils varies from deep black to light black.
•  Black soils have the high water-retaining capacity.
• They are extremely compact and tenacious when wet, and develop wide cracks when dry.
• In other words, they swell greatly and become sticky when wet in the rainy season.
• When the soil is wet, it becomes difficult to plough the field as the plough gets stuck in the mud.
• In the dry season, the moisture evaporates, the soil shrinks and develops wide cracks, often 10- 15 cm deep.
• The soils are well suited for the cultivation of cotton, pulses, millets, linseed, castor, tobacco, sugarcane, vegetables, and citrus fruits.

Alluvial soil

• These soils are mainly derived from the debris brought down from the Himalayas or from the silt left out by the retreating sea.
• Alluvial soils are divided into 
  •  Khadar soil:
    • The khadar soils are low-lying, frequently inundated by floods during the rainy season.
    • Thus, the khadar occupies the flood plains of the rivers and is enriched by fresh silt deposits every year. The khadar tracts are generally rich in
      concretions, and nodules of impure calcium carbonate or Kankar.
  • Bhangar soil :
    • It is generally well-drained but contains concretion (kankars) of impure calcium carbonate.
    • The soil texture varies from loamy soil to clay-loam.

Laterite soil

• These are the typical soils of the monsoon climate which is characterised by seasonal rainfall.
• The alternating wet and dry seasons lead to the leaching away of the siliceous matter of the rocks leading to the formation of such soils.
• The red colour of the soils is due to the presence of iron-oxide.

Yellow Soil

• The red soil looks yellow when it occurs in a hydrated form.
• Often, their upper layer is red and the lower layer is yellow. 

The hemorrhage that accompanies menses occurs because the endometrium is a richly vascularized tissue. The rupture of blood vessels of the uterine mucosa during the menstrual desquamation causes the bleeding.

(b) Fear of time

(a) cloi-stered

(d) psy-chol-o-gy

The correct answer is Patliputra.

• Aryabhatta was a famous Indian mathematician and astronomer, born in a place called Taregana, in Bihar.
• Taregana which literally means songs of stars in Bihari is a small place situated nearly 30 km from Patna, which was then known as Kusumpura later Pataliputra, the capital of the Gupta Empire.

• Aryabhata was the first in the line of great mathematician-astronomers from the classical age of Indian mathematics and Indian astronomy.
• His works include the Aryabhaṭiya (499 CE, when he was 23 years old) and the Arya-Siddhanta.
• The works of Aryabhata dealt with mainly mathematics and astronomy.
• The mathematical part of the Aryabhatiya covers arithmetic, algebra, plane trigonometry, and spherical trigonometry.
• It also contains continued fractions, quadratic equations, sums of power series, and a table of sines.
• Aryabhata did solve quadratic and indeterminate equations, and provided an extremely accurate approximation for “pi”.

(d) The one who collects coins

(a) phi-loI-o-gy

(a) The combined mixture of light, loose and unstructured rock crust (shell powder) and fine granules found on the earth’s surface is called soil.

(b) The primary rocks in the country consist of lofty rocks of the northern plains or lava-formed rocks of the plateau. They contain various types of minerals. Therefore, they make good soil. The colour, formation, texture, etc. of the soil formed by the primary rocks depends on how long the rocks are being affected and by what kind of climate. In a state like West Bengal, the spil is highly developed due to the effects of chemical reactions in the climate and humus. But in dry area like Rajasthan, due to lack of vegetation, soil fertility decreases. Likewise, soil erosion is more in areas with high rainfall and high winds. Fertility decreases as a result.