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NEET ]1[ Contd...
NEET Biology Class 12 - Human Reproduction Ultra-Hard Question Bank
Instructions:
- Each question has four options (1), (2), (3), (4). Choose the most correct answer.
- Each correct answer carries 4 marks.
- Each wrong answer will deduct 1 marks.
- Unanswered questions will not be penalised.
1.Consider the following statements regarding human reproductive events (Question 1):
I. Humans are sexually reproducing and viviparous organisms.
II. The reproductive events in humans include formation of gametes (gametogenesis), i.e.,
sperms in males and ovum in females.
III. The reproductive events in humans occur before puberty.
IV. Sperm formation ceases in old men around the age of fifty years, while formation of ovum
continues throughout life.
Which of the statements given above are incorrect according to the NCERT text?
I. Humans are sexually reproducing and viviparous organisms.
II. The reproductive events in humans include formation of gametes (gametogenesis), i.e.,
sperms in males and ovum in females.
III. The reproductive events in humans occur before puberty.
IV. Sperm formation ceases in old men around the age of fifty years, while formation of ovum
continues throughout life.
Which of the statements given above are incorrect according to the NCERT text?
2.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 2):
Assertion (A): The male reproductive system includes a pair of testes along with accessory ducts,
glands, and the external genitalia, all located in the pelvis region.
Reason (R): The testes are situated inside the abdominal cavity within a pouch called scrotum to
maintain low temperature.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 2):
Assertion (A): The male reproductive system includes a pair of testes along with accessory ducts,
glands, and the external genitalia, all located in the pelvis region.
Reason (R): The testes are situated inside the abdominal cavity within a pouch called scrotum to
maintain low temperature.
In the light of the above statements, choose the correct answer:
3.Consider the following statements regarding the structural details of human testes
(Question 3):
I. The scrotum helps in maintaining the high temperature of the testes necessary for
spermatogenesis.
II. In adults, each testis is oval in shape, with a length of about 4 to 5 cm and a width of about 2
to 3 cm.
III. The testis is covered by a thin membranous covering.
IV. Each testis has about 250 compartments called testicular lobules.
Which of the statements given above are correct according to the NCERT text?
(Question 3):
I. The scrotum helps in maintaining the high temperature of the testes necessary for
spermatogenesis.
II. In adults, each testis is oval in shape, with a length of about 4 to 5 cm and a width of about 2
to 3 cm.
III. The testis is covered by a thin membranous covering.
IV. Each testis has about 250 compartments called testicular lobules.
Which of the statements given above are correct according to the NCERT text?
4.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 4):
Assertion (A): Each seminiferous tubule is lined on its inside by male germ cells
(spermatogonia) and Sertoli cells.
Reason (R): Male germ cells undergo meiotic divisions finally leading to sperm formation, while
Sertoli cells provide nutrition to the germ cells.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 4):
Assertion (A): Each seminiferous tubule is lined on its inside by male germ cells
(spermatogonia) and Sertoli cells.
Reason (R): Male germ cells undergo meiotic divisions finally leading to sperm formation, while
Sertoli cells provide nutrition to the germ cells.
In the light of the above statements, choose the correct answer:
5.Consider the following statements regarding the region outside the seminiferous tubules
(Question 5):
I. The regions outside the seminiferous tubules are called interstitial spaces.
II. Interstitial spaces contain large blood vessels and interstitial cells or Leydig cells.
III. Leydig cells synthesise and secrete testicular hormones called androgens.
IV. Other immunologically competent cells are also present in the interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
(Question 5):
I. The regions outside the seminiferous tubules are called interstitial spaces.
II. Interstitial spaces contain large blood vessels and interstitial cells or Leydig cells.
III. Leydig cells synthesise and secrete testicular hormones called androgens.
IV. Other immunologically competent cells are also present in the interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
6.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 6):
Assertion (A): The male sex accessory ducts include rete testis, vasa efferentia, epididymis, and
vas deferens.
Reason (R): These accessory ducts store and transport the sperms from the testis to the outside
through urethra.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 6):
Assertion (A): The male sex accessory ducts include rete testis, vasa efferentia, epididymis, and
vas deferens.
Reason (R): These accessory ducts store and transport the sperms from the testis to the outside
through urethra.
In the light of the above statements, choose the correct answer:
7.Consider the following statements regarding the pathway of sperm through the male
accessory ducts (Question 7):
I. The seminiferous tubules of the testis open into the vasa efferentia through rete testis.
II. The vasa efferentia leave the testis and open into epididymis located along the anterior
surface of each testis.
III. The epididymis leads to vas deferens that ascends to the abdomen and loops over the
urinary bladder.
IV. The vas deferens receives a duct from the prostate gland and opens into urethra as the
ejaculatory duct.
Which of the statements given above are correct according to the NCERT text?
accessory ducts (Question 7):
I. The seminiferous tubules of the testis open into the vasa efferentia through rete testis.
II. The vasa efferentia leave the testis and open into epididymis located along the anterior
surface of each testis.
III. The epididymis leads to vas deferens that ascends to the abdomen and loops over the
urinary bladder.
IV. The vas deferens receives a duct from the prostate gland and opens into urethra as the
ejaculatory duct.
Which of the statements given above are correct according to the NCERT text?
8.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 8):
Assertion (A): The urethra originates from the urinary bladder and extends through the penis
to its external opening called urethral meatus.
Reason (R): The semen is transported from the ejaculatory duct directly to the glans penis
without passing through the urethral canal.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 8):
Assertion (A): The urethra originates from the urinary bladder and extends through the penis
to its external opening called urethral meatus.
Reason (R): The semen is transported from the ejaculatory duct directly to the glans penis
without passing through the urethral canal.
In the light of the above statements, choose the correct answer:
9.Consider the following statements regarding the cells of the human testis (Question 9):
I. Male germ cells (spermatogonia) undergo meiotic divisions to increase their numbers in the
seminiferous tubules.
II. Sertoli cells provide nutrition to the dividing germ cells.
III. Leydig cells reside in the interstitial spaces and secrete testicular hormones called
gonadotropins.
IV. Immunologically competent cells are present in the interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
I. Male germ cells (spermatogonia) undergo meiotic divisions to increase their numbers in the
seminiferous tubules.
II. Sertoli cells provide nutrition to the dividing germ cells.
III. Leydig cells reside in the interstitial spaces and secrete testicular hormones called
gonadotropins.
IV. Immunologically competent cells are present in the interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
10.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 10):
Assertion (A): The scrotum plays a crucial physiological role by maintaining the temperature of
the testes 2–2.5°C lower than the normal internal body temperature.
Reason (R): A lower temperature than the normal internal body temperature is an absolute
prerequisite for the process of spermatogenesis.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 10):
Assertion (A): The scrotum plays a crucial physiological role by maintaining the temperature of
the testes 2–2.5°C lower than the normal internal body temperature.
Reason (R): A lower temperature than the normal internal body temperature is an absolute
prerequisite for the process of spermatogenesis.
In the light of the above statements, choose the correct answer:
11.Consider the following statements regarding the quantitative and structural parameters of
human testes (Question 11):
I. Each testis is oval in shape with a length of 2 to 3 cm and a width of 4 to 5 cm.
II. Each testis contains about 250 highly coiled compartments called testicular lobules.
III. Each testicular lobule contains one to three highly coiled seminiferous tubules in which
sperms are produced.
IV. The testes are situated outside the abdominal cavity in a pouch called scrotum.
Which of the statements given above are correct according to the NCERT text?
human testes (Question 11):
I. Each testis is oval in shape with a length of 2 to 3 cm and a width of 4 to 5 cm.
II. Each testis contains about 250 highly coiled compartments called testicular lobules.
III. Each testicular lobule contains one to three highly coiled seminiferous tubules in which
sperms are produced.
IV. The testes are situated outside the abdominal cavity in a pouch called scrotum.
Which of the statements given above are correct according to the NCERT text?
12.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 12):
Assertion (A): The seminiferous tubules of the testis open into the vasa efferentia through rete
testis.
Reason (R): Rete testis is a male sex accessory gland that secretes seminal plasma rich in
fructose.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 12):
Assertion (A): The seminiferous tubules of the testis open into the vasa efferentia through rete
testis.
Reason (R): Rete testis is a male sex accessory gland that secretes seminal plasma rich in
fructose.
In the light of the above statements, choose the correct answer:
13.Consider the following statements regarding the male accessory glands and external
genitalia (Question 13):
I. The penis is made up of special tissue that helps in erection to facilitate insemination.
II. The male accessory glands include paired seminal vesicles, paired prostate, and paired
bulbourethral glands.
III. Secretions of the male accessory glands constitute the seminal plasma which is rich in
glucose, calcium, and certain enzymes.
IV. The secretions of bulbourethral glands help in the lubrication of the penis.
Which of the statements given above are incorrect according to the NCERT text?
genitalia (Question 13):
I. The penis is made up of special tissue that helps in erection to facilitate insemination.
II. The male accessory glands include paired seminal vesicles, paired prostate, and paired
bulbourethral glands.
III. Secretions of the male accessory glands constitute the seminal plasma which is rich in
glucose, calcium, and certain enzymes.
IV. The secretions of bulbourethral glands help in the lubrication of the penis.
Which of the statements given above are incorrect according to the NCERT text?
14.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 14):
Assertion (A): The enlarged end of the penis is called the glans penis.
Reason (R): The glans penis is covered by a loose fold of skin called foreskin.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 14):
Assertion (A): The enlarged end of the penis is called the glans penis.
Reason (R): The glans penis is covered by a loose fold of skin called foreskin.
In the light of the above statements, choose the correct answer:
15.Consider the following statements regarding the female ovaries (Question 15):
I. Ovaries are the primary female sex organs that produce the female gamete (ovum) and
several steroid hormones.
II. The ovaries are located one on each side of the upper abdomen.
III. Each ovary is about 2 to 4 cm in length and is connected to the pelvic wall and uterus by
ligaments.
IV. Each ovary is covered by a thick epithelium which encloses the ovarian stroma.
Which of the statements given above are correct according to the NCERT text?
I. Ovaries are the primary female sex organs that produce the female gamete (ovum) and
several steroid hormones.
II. The ovaries are located one on each side of the upper abdomen.
III. Each ovary is about 2 to 4 cm in length and is connected to the pelvic wall and uterus by
ligaments.
IV. Each ovary is covered by a thick epithelium which encloses the ovarian stroma.
Which of the statements given above are correct according to the NCERT text?
16.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 16):
Assertion (A): Each ovary contains a stroma that is divided into two distinct anatomical zones.
Reason (R): The ovarian stroma is divided into a peripheral medulla and an inner cortex.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 16):
Assertion (A): Each ovary contains a stroma that is divided into two distinct anatomical zones.
Reason (R): The ovarian stroma is divided into a peripheral medulla and an inner cortex.
In the light of the above statements, choose the correct answer:
17.Consider the following statements regarding the fallopian tubes (oviducts) (Question 17):
I. Each fallopian tube is about 10-12 cm long and extends from the periphery of each ovary to
the uterus.
II. The part of the fallopian tube closer to the ovary is the funnel-shaped ampulla.
III. The edges of the infundibulum possess finger-like projections called fimbriae, which help in
collection of the ovum after ovulation.
IV. The infundibulum leads to a wider part of the oviduct called isthmus.
Which of the statements given above are incorrect according to the NCERT text?
I. Each fallopian tube is about 10-12 cm long and extends from the periphery of each ovary to
the uterus.
II. The part of the fallopian tube closer to the ovary is the funnel-shaped ampulla.
III. The edges of the infundibulum possess finger-like projections called fimbriae, which help in
collection of the ovum after ovulation.
IV. The infundibulum leads to a wider part of the oviduct called isthmus.
Which of the statements given above are incorrect according to the NCERT text?
18.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 18):
Assertion (A): The uterus is single and its shape is like an inverted pear.
Reason (R): The uterus is supported by ligaments attached to the pelvic wall.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 18):
Assertion (A): The uterus is single and its shape is like an inverted pear.
Reason (R): The uterus is supported by ligaments attached to the pelvic wall.
In the light of the above statements, choose the correct answer:
19.Consider the following statements regarding the human uterus (Question 19):
I. The cavity of the cervix is called the cervical canal, which along with the vagina forms the
birth canal.
II. The wall of the uterus has three layers of tissue: perimetrium, myometrium, and
endometrium.
III. The perimetrium is the middle thick layer of smooth muscle that exhibits strong contraction
during delivery.
IV. The endometrium is the inner glandular layer that undergoes cyclical changes during the
menstrual cycle.
Which of the statements given above are correct according to the NCERT text?
I. The cavity of the cervix is called the cervical canal, which along with the vagina forms the
birth canal.
II. The wall of the uterus has three layers of tissue: perimetrium, myometrium, and
endometrium.
III. The perimetrium is the middle thick layer of smooth muscle that exhibits strong contraction
during delivery.
IV. The endometrium is the inner glandular layer that undergoes cyclical changes during the
menstrual cycle.
Which of the statements given above are correct according to the NCERT text?
20.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 20):
Assertion (A): The presence or absence of the hymen is not a reliable indicator of virginity or
sexual experience in human females.
Reason (R): In some women, the hymen persists even after coitus, and it can also be broken by
sudden falls, vaginal tampons, or active sports.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 20):
Assertion (A): The presence or absence of the hymen is not a reliable indicator of virginity or
sexual experience in human females.
Reason (R): In some women, the hymen persists even after coitus, and it can also be broken by
sudden falls, vaginal tampons, or active sports.
In the light of the above statements, choose the correct answer:
21.Consider the following statements regarding the female external genitalia (Question 21):
I. The female external genitalia include mons pubis, labia majora, labia minora, hymen, and
clitoris.
II. Mons pubis is a cushion of fatty tissue covered by skin and pubic hair.
III. The labia majora are paired folds of tissue under the labia minora.
IV. The clitoris is a tiny finger-like structure which lies at the upper junction of the two labia
minora above the urethral opening.
Which of the statements given above are correct according to the NCERT text?
I. The female external genitalia include mons pubis, labia majora, labia minora, hymen, and
clitoris.
II. Mons pubis is a cushion of fatty tissue covered by skin and pubic hair.
III. The labia majora are paired folds of tissue under the labia minora.
IV. The clitoris is a tiny finger-like structure which lies at the upper junction of the two labia
minora above the urethral opening.
Which of the statements given above are correct according to the NCERT text?
22.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 22):
Assertion (A): Mammary glands are integrated structurally and functionally with the primary
female reproductive organs and accessory ducts.
Reason (R): A functional mammary gland is characteristic of all female mammals.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 22):
Assertion (A): Mammary glands are integrated structurally and functionally with the primary
female reproductive organs and accessory ducts.
Reason (R): A functional mammary gland is characteristic of all female mammals.
In the light of the above statements, choose the correct answer:
23.Consider the following statements regarding the pathway of milk in the mammary gland
(Question 23):
I. The glandular tissue of each breast is divided into 15–20 mammary lobes containing clusters
of cells called alveoli.
II. The cells of alveoli secrete milk, which is stored in the cavities (lumens) of alveoli.
III. The alveoli open into mammary tubules, which join to form a mammary duct.
IV. Several mammary ducts join to form a wider mammary ampulla which opens directly at the
nipple.
Which of the statements given above are correct according to the NCERT text?
(Question 23):
I. The glandular tissue of each breast is divided into 15–20 mammary lobes containing clusters
of cells called alveoli.
II. The cells of alveoli secrete milk, which is stored in the cavities (lumens) of alveoli.
III. The alveoli open into mammary tubules, which join to form a mammary duct.
IV. Several mammary ducts join to form a wider mammary ampulla which opens directly at the
nipple.
Which of the statements given above are correct according to the NCERT text?
24.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 24):
Assertion (A): The milk secreted by the alveoli is stored in their cavities (lumens) rather than
within the cells themselves.
Reason (R): The cells of the alveoli secrete milk when stimulated, and the alveoli open into
mammary ducts directly.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 24):
Assertion (A): The milk secreted by the alveoli is stored in their cavities (lumens) rather than
within the cells themselves.
Reason (R): The cells of the alveoli secrete milk when stimulated, and the alveoli open into
mammary ducts directly.
In the light of the above statements, choose the correct answer:
25.Consider the following statements regarding the cellular divisions in human
spermatogenesis (Question 25):
I. Spermatogonia present on the inside wall of seminiferous tubules multiply by mitotic division
and increase in numbers.
II. Each spermatogonium is diploid and contains 46 chromosomes.
III. A primary spermatocyte completes the first meiotic division leading to the formation of two
unequal, haploid cells called secondary spermatocytes.
IV. The secondary spermatocytes have 23 chromosomes each and undergo the second meiotic
division to produce four equal, haploid spermatids.
Which of the statements given above are correct according to the NCERT text?
spermatogenesis (Question 25):
I. Spermatogonia present on the inside wall of seminiferous tubules multiply by mitotic division
and increase in numbers.
II. Each spermatogonium is diploid and contains 46 chromosomes.
III. A primary spermatocyte completes the first meiotic division leading to the formation of two
unequal, haploid cells called secondary spermatocytes.
IV. The secondary spermatocytes have 23 chromosomes each and undergo the second meiotic
division to produce four equal, haploid spermatids.
Which of the statements given above are correct according to the NCERT text?
26.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 26):
Assertion (A): The transformation of spermatids into spermatozoa is known as spermiogenesis.
Reason (R): After the completion of spermiogenesis, sperm heads become embedded in the
Sertoli cells, and are finally released from the seminiferous tubules by the process of
spermiation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 26):
Assertion (A): The transformation of spermatids into spermatozoa is known as spermiogenesis.
Reason (R): After the completion of spermiogenesis, sperm heads become embedded in the
Sertoli cells, and are finally released from the seminiferous tubules by the process of
spermiation.
In the light of the above statements, choose the correct answer:
27.Consider the following statements regarding the hormonal control of spermatogenesis
(Question 27):
I. Spermatogenesis starts at the age of puberty due to a significant increase in the secretion of
gonadotropin releasing hormone (GnRH).
II. GnRH is a pituitary hormone that acts on the hypothalamus to stimulate gonadotropins.
III. Secretion of LH and FSH is stimulated by the action of increased levels of GnRH at the
anterior pituitary gland.
IV. LH acts on the Leydig cells, while FSH acts on the Sertoli cells.
Which of the statements given above are correct according to the NCERT text?
(Question 27):
I. Spermatogenesis starts at the age of puberty due to a significant increase in the secretion of
gonadotropin releasing hormone (GnRH).
II. GnRH is a pituitary hormone that acts on the hypothalamus to stimulate gonadotropins.
III. Secretion of LH and FSH is stimulated by the action of increased levels of GnRH at the
anterior pituitary gland.
IV. LH acts on the Leydig cells, while FSH acts on the Sertoli cells.
Which of the statements given above are correct according to the NCERT text?
28.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 28):
Assertion (A): Luteinising hormone (LH) plays an essential stimulatory role in the male
germinal epithelium by acting on Leydig cells.
Reason (R): LH stimulates the synthesis and secretion of androgens from Leydig cells, and
androgens in turn stimulate the process of spermatogenesis.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 28):
Assertion (A): Luteinising hormone (LH) plays an essential stimulatory role in the male
germinal epithelium by acting on Leydig cells.
Reason (R): LH stimulates the synthesis and secretion of androgens from Leydig cells, and
androgens in turn stimulate the process of spermatogenesis.
In the light of the above statements, choose the correct answer:
29.Consider the following statements regarding FSH and Sertoli cells (Question 29):
I. FSH acts on the Sertoli cells and stimulates the process of spermatogenesis directly.
II. FSH stimulates the secretion of some factors which help in the process of spermiogenesis.
III. After spermiogenesis, sperm heads become embedded in the Sertoli cells.
IV. Spermiation is the process where sperms are released from the Sertoli cells into the
interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
I. FSH acts on the Sertoli cells and stimulates the process of spermatogenesis directly.
II. FSH stimulates the secretion of some factors which help in the process of spermiogenesis.
III. After spermiogenesis, sperm heads become embedded in the Sertoli cells.
IV. Spermiation is the process where sperms are released from the Sertoli cells into the
interstitial spaces.
Which of the statements given above are correct according to the NCERT text?
30.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 30):
Assertion (A): During spermiogenesis, haploid spermatids undergo mitotic divisions to increase
the number of spermatozoa.
Reason (R): The spermatids are transformed into spermatozoa by undergoing structural and
morphological changes.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 30):
Assertion (A): During spermiogenesis, haploid spermatids undergo mitotic divisions to increase
the number of spermatozoa.
Reason (R): The spermatids are transformed into spermatozoa by undergoing structural and
morphological changes.
In the light of the above statements, choose the correct answer:
31.Consider the following statements regarding the division symmetry and product ploidy in
human spermatogenesis (Question 31):
I. Primary spermatocytes are diploid cells with 46 chromosomes.
II. Secondary spermatocytes are haploid cells that are formed from the unequal division of
primary spermatocytes.
III. The second meiotic division of secondary spermatocytes produces four equal, haploid
spermatids.
IV. The spermatids have 23 chromosomes each before transforming into sperms.
Which of the statements given above are correct according to the NCERT text?
human spermatogenesis (Question 31):
I. Primary spermatocytes are diploid cells with 46 chromosomes.
II. Secondary spermatocytes are haploid cells that are formed from the unequal division of
primary spermatocytes.
III. The second meiotic division of secondary spermatocytes produces four equal, haploid
spermatids.
IV. The spermatids have 23 chromosomes each before transforming into sperms.
Which of the statements given above are correct according to the NCERT text?
32.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 32):
Assertion (A): Spermatogenesis starts at the age of puberty rather than during the embryonic
development stage.
Reason (R): Puberty is marked by a significant increase in the secretion of gonadotropin
releasing hormone (GnRH) from the hypothalamus.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 32):
Assertion (A): Spermatogenesis starts at the age of puberty rather than during the embryonic
development stage.
Reason (R): Puberty is marked by a significant increase in the secretion of gonadotropin
releasing hormone (GnRH) from the hypothalamus.
In the light of the above statements, choose the correct answer:
33.Consider the following statements regarding the role of Sertoli cells in male reproduction
(Question 33):
I. Sertoli cells provide nutrition to the dividing germ cells.
II. FSH acts on Sertoli cells to stimulate the secretion of factors which help in the process of
spermiation.
III. After spermiogenesis, sperm heads become embedded in the Sertoli cells.
IV. Spermiation involves the active release of spermatozoa from the Sertoli cells into the
seminiferous tubules.
Which of the statements given above are correct according to the NCERT text?
(Question 33):
I. Sertoli cells provide nutrition to the dividing germ cells.
II. FSH acts on Sertoli cells to stimulate the secretion of factors which help in the process of
spermiation.
III. After spermiogenesis, sperm heads become embedded in the Sertoli cells.
IV. Spermiation involves the active release of spermatozoa from the Sertoli cells into the
seminiferous tubules.
Which of the statements given above are correct according to the NCERT text?
34.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 34):
Assertion (A): Leydig cells synthesise and secrete testicular hormones called androgens under
the direct influence of luteinising hormone (LH).
Reason (R): Leydig cells are located in the interstitial spaces outside the seminiferous tubules.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 34):
Assertion (A): Leydig cells synthesise and secrete testicular hormones called androgens under
the direct influence of luteinising hormone (LH).
Reason (R): Leydig cells are located in the interstitial spaces outside the seminiferous tubules.
In the light of the above statements, choose the correct answer:
35.Consider the following statements regarding the chromosomal status of cells during
spermatogenesis (Question 35):
I. Spermatogonia are diploid cells containing 46 chromosomes.
II. Primary spermatocytes are diploid cells containing 46 chromosomes.
III. Secondary spermatocytes are haploid cells containing 23 chromosomes.
IV. Spermatids are haploid cells containing 46 chromatids, which is why they are transformed
into spermatozoa with 23 chromosomes.
Which of the statements given above are correct according to the NCERT text?
spermatogenesis (Question 35):
I. Spermatogonia are diploid cells containing 46 chromosomes.
II. Primary spermatocytes are diploid cells containing 46 chromosomes.
III. Secondary spermatocytes are haploid cells containing 23 chromosomes.
IV. Spermatids are haploid cells containing 46 chromatids, which is why they are transformed
into spermatozoa with 23 chromosomes.
Which of the statements given above are correct according to the NCERT text?
36.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 36):
Assertion (A): Sertoli cells undergo meiotic division to provide haploid nuclei for the developing
germ cells.
Reason (R): Sertoli cells are structural support cells that provide nutrition to the dividing germ
cells inside the seminiferous tubules.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 36):
Assertion (A): Sertoli cells undergo meiotic division to provide haploid nuclei for the developing
germ cells.
Reason (R): Sertoli cells are structural support cells that provide nutrition to the dividing germ
cells inside the seminiferous tubules.
In the light of the above statements, choose the correct answer:
37.Consider the following statements regarding the structural parts of a human sperm
(Question 37):
I. The sperm is a microscopic structure composed of a head, neck, a middle piece, and a tail.
II. A cell wall envelops the whole body of the sperm to provide structural rigidity.
III. The sperm head contains an elongated haploid nucleus, the anterior portion of which is
covered by a cap-like structure called acrosome.
IV. The acrosome is filled with enzymes that help in the fertilisation of the ovum.
Which of the statements given above are correct according to the NCERT text?
(Question 37):
I. The sperm is a microscopic structure composed of a head, neck, a middle piece, and a tail.
II. A cell wall envelops the whole body of the sperm to provide structural rigidity.
III. The sperm head contains an elongated haploid nucleus, the anterior portion of which is
covered by a cap-like structure called acrosome.
IV. The acrosome is filled with enzymes that help in the fertilisation of the ovum.
Which of the statements given above are correct according to the NCERT text?
38.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 38):
Assertion (A): The middle piece of the human sperm is functionally critical for the transport of
the haploid nucleus to the site of fertilisation.
Reason (R): The middle piece possesses numerous mitochondria, which produce energy for the
movement of the tail that facilitates sperm motility essential for fertilisation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 38):
Assertion (A): The middle piece of the human sperm is functionally critical for the transport of
the haploid nucleus to the site of fertilisation.
Reason (R): The middle piece possesses numerous mitochondria, which produce energy for the
movement of the tail that facilitates sperm motility essential for fertilisation.
In the light of the above statements, choose the correct answer:
39.Consider the following statements regarding the parameters of human ejaculation and
semen (Question 39):
I. The human male ejaculates about 200 to 300 million sperms during a single coitus.
II. For normal fertility, at least 40 per cent of sperms must have normal shape and size.
III. At least 60 per cent of sperms must show vigorous motility for normal fertility.
IV. Secretions of epididymis, vas deferens, seminal vesicle, and prostate are essential for
maturation and motility of sperms.
Which of the statements given above are correct according to the NCERT text?
semen (Question 39):
I. The human male ejaculates about 200 to 300 million sperms during a single coitus.
II. For normal fertility, at least 40 per cent of sperms must have normal shape and size.
III. At least 60 per cent of sperms must show vigorous motility for normal fertility.
IV. Secretions of epididymis, vas deferens, seminal vesicle, and prostate are essential for
maturation and motility of sperms.
Which of the statements given above are correct according to the NCERT text?
40.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 40):
Assertion (A): The seminal plasma along with the spermatozoa constitute the semen.
Reason (R): The functions of male sex accessory ducts and glands are maintained by the
testicular hormones (androgens).
In the light of the above statements, choose the correct answer:
Reason (R) (Question 40):
Assertion (A): The seminal plasma along with the spermatozoa constitute the semen.
Reason (R): The functions of male sex accessory ducts and glands are maintained by the
testicular hormones (androgens).
In the light of the above statements, choose the correct answer:
41.Consider the following statements regarding the initiation of oogenesis in human females
(Question 41):
I. Oogenesis is initiated during the embryonic development stage.
II. A couple of million gamete mother cells (oogonia) are formed within each fetal ovary.
III. Oogonia continue to divide, multiply, and are actively added after birth.
IV. Oogonia enter into prophase-I of the meiotic division and get temporarily arrested at that
stage, called primary oocytes.
Which of the statements given above are correct according to the NCERT text?
(Question 41):
I. Oogenesis is initiated during the embryonic development stage.
II. A couple of million gamete mother cells (oogonia) are formed within each fetal ovary.
III. Oogonia continue to divide, multiply, and are actively added after birth.
IV. Oogonia enter into prophase-I of the meiotic division and get temporarily arrested at that
stage, called primary oocytes.
Which of the statements given above are correct according to the NCERT text?
42.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 42):
Assertion (A): At puberty, only 60,000–80,000 primary follicles are left in each ovary of a human
female.
Reason (R): A large number of primary follicles degenerate during the developmental phase
from birth to puberty.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 42):
Assertion (A): At puberty, only 60,000–80,000 primary follicles are left in each ovary of a human
female.
Reason (R): A large number of primary follicles degenerate during the developmental phase
from birth to puberty.
In the light of the above statements, choose the correct answer:
43.Consider the following statements regarding the developmental stages of ovarian follicles
(Question 43):
I. Primary follicles get surrounded by more layers of granulosa cells and a new theca to become
secondary follicles.
II. Secondary follicles transform into tertiary follicles, which are characterised by a fluid-filled
cavity called antrum.
III. In the tertiary follicle, the theca layer is organised into an inner theca externa and an outer
theca interna.
IV. The primary oocyte within the tertiary follicle grows in size and completes its first meiotic
division.
Which of the statements given above are correct according to the NCERT text?
(Question 43):
I. Primary follicles get surrounded by more layers of granulosa cells and a new theca to become
secondary follicles.
II. Secondary follicles transform into tertiary follicles, which are characterised by a fluid-filled
cavity called antrum.
III. In the tertiary follicle, the theca layer is organised into an inner theca externa and an outer
theca interna.
IV. The primary oocyte within the tertiary follicle grows in size and completes its first meiotic
division.
Which of the statements given above are correct according to the NCERT text?
44.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 44):
Assertion (A): The first meiotic division of the primary oocyte within the tertiary follicle is an
unequal division.
Reason (R): It results in the formation of a large haploid secondary oocyte and a tiny haploid
first polar body.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 44):
Assertion (A): The first meiotic division of the primary oocyte within the tertiary follicle is an
unequal division.
Reason (R): It results in the formation of a large haploid secondary oocyte and a tiny haploid
first polar body.
In the light of the above statements, choose the correct answer:
45.Consider the following statements regarding the products of the first meiotic division in
oogenesis (Question 45):
I. The secondary oocyte retains the bulk of the nutrient-rich cytoplasm of the primary oocyte.
II. The first polar body born out of the first meiotic division is known to divide further to form
secondary polar bodies.
III. The tertiary follicle further changes into the mature follicle or Graafian follicle.
IV. The secondary oocyte forms a new membrane called zona pellucida surrounding it.
Which of the statements given above are correct according to the NCERT text?
oogenesis (Question 45):
I. The secondary oocyte retains the bulk of the nutrient-rich cytoplasm of the primary oocyte.
II. The first polar body born out of the first meiotic division is known to divide further to form
secondary polar bodies.
III. The tertiary follicle further changes into the mature follicle or Graafian follicle.
IV. The secondary oocyte forms a new membrane called zona pellucida surrounding it.
Which of the statements given above are correct according to the NCERT text?
46.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 46):
Assertion (A): The secondary oocyte is released from the ovary by the rupture of the mature
Graafian follicle.
Reason (R): The process of releasing the secondary oocyte (ovum) from the ovary is called
ovulation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 46):
Assertion (A): The secondary oocyte is released from the ovary by the rupture of the mature
Graafian follicle.
Reason (R): The process of releasing the secondary oocyte (ovum) from the ovary is called
ovulation.
In the light of the above statements, choose the correct answer:
47.Consider the following statements comparing human spermatogenesis and oogenesis
(Question 47):
I. Spermatogenesis starts at puberty, whereas oogenesis is initiated during embryonic
development.
II. Spermatogonia multiply throughout life, whereas no more oogonia are formed and added
after birth.
III. Meiotic divisions in spermatogenesis are equal, whereas meiotic divisions in oogenesis are
unequal.
IV. Both processes result in the formation of four functional gametes from a single primary
gametocyte.
Which of the statements given above are correct according to the NCERT text?
(Question 47):
I. Spermatogenesis starts at puberty, whereas oogenesis is initiated during embryonic
development.
II. Spermatogonia multiply throughout life, whereas no more oogonia are formed and added
after birth.
III. Meiotic divisions in spermatogenesis are equal, whereas meiotic divisions in oogenesis are
unequal.
IV. Both processes result in the formation of four functional gametes from a single primary
gametocyte.
Which of the statements given above are correct according to the NCERT text?
48.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 48):
Assertion (A): The first polar body formed during the first meiotic division of oogenesis is
haploid in nature.
Reason (R): The primary oocyte undergoes mitotic division within the tertiary follicle to
maintain chromosomal count.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 48):
Assertion (A): The first polar body formed during the first meiotic division of oogenesis is
haploid in nature.
Reason (R): The primary oocyte undergoes mitotic division within the tertiary follicle to
maintain chromosomal count.
In the light of the above statements, choose the correct answer:
49.Consider the following statements regarding the human female reproductive cycle
(Question 49):
I. The reproductive cycle in female primates (e.g. monkeys, apes and human beings) is called the
menstrual cycle.
II. The first menstruation begins at puberty and is called menopause.
III. In human females, menstruation is repeated at an average interval of about 28/29 days.
IV. One ovum is released (ovulation) during the middle of each menstrual cycle.
Which of the statements given above are correct according to the NCERT text?
(Question 49):
I. The reproductive cycle in female primates (e.g. monkeys, apes and human beings) is called the
menstrual cycle.
II. The first menstruation begins at puberty and is called menopause.
III. In human females, menstruation is repeated at an average interval of about 28/29 days.
IV. One ovum is released (ovulation) during the middle of each menstrual cycle.
Which of the statements given above are correct according to the NCERT text?
50.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 50):
Assertion (A): Lack of menstruation in a sexually active human female is a definitive, absolute,
and exclusive indicator of pregnancy.
Reason (R): Menstruation only occurs if the released ovum is not fertilised.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 50):
Assertion (A): Lack of menstruation in a sexually active human female is a definitive, absolute,
and exclusive indicator of pregnancy.
Reason (R): Menstruation only occurs if the released ovum is not fertilised.
In the light of the above statements, choose the correct answer:
51.Consider the following statements regarding the follicular phase of the menstrual cycle
(Question 51):
I. The menstrual phase is followed by the follicular phase.
II. During this phase, the primary follicles in the ovary grow to become a fully mature Graafian
follicle.
III. Simultaneously, the endometrium of the uterus degenerates through proliferation.
IV. These changes in the ovary and the uterus are induced by changes in the levels of pituitary
and ovarian hormones.
Which of the statements given above are correct according to the NCERT text?
(Question 51):
I. The menstrual phase is followed by the follicular phase.
II. During this phase, the primary follicles in the ovary grow to become a fully mature Graafian
follicle.
III. Simultaneously, the endometrium of the uterus degenerates through proliferation.
IV. These changes in the ovary and the uterus are induced by changes in the levels of pituitary
and ovarian hormones.
Which of the statements given above are correct according to the NCERT text?
52.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 52):
Assertion (A): Rapid secretion of luteinising hormone (LH) leading to its maximum level during
the mid-cycle induces rupture of the Graafian follicle.
Reason (R): Both LH and FSH attain a peak level in the middle of the cycle (about 14th day).
In the light of the above statements, choose the correct answer:
Reason (R) (Question 52):
Assertion (A): Rapid secretion of luteinising hormone (LH) leading to its maximum level during
the mid-cycle induces rupture of the Graafian follicle.
Reason (R): Both LH and FSH attain a peak level in the middle of the cycle (about 14th day).
In the light of the above statements, choose the correct answer:
53.Consider the following statements regarding the luteal phase of the menstrual cycle
(Question 53):
I. The ovulatory phase is followed by the luteal phase.
II. During this phase, the remaining parts of the Graafian follicle transform as the corpus
luteum.
III. The corpus luteum secretes large amounts of estrogen which is essential for maintenance of
the endometrium.
IV. An intact endometrium is necessary for implantation of the fertilised ovum.
Which of the statements given above are correct according to the NCERT text?
(Question 53):
I. The ovulatory phase is followed by the luteal phase.
II. During this phase, the remaining parts of the Graafian follicle transform as the corpus
luteum.
III. The corpus luteum secretes large amounts of estrogen which is essential for maintenance of
the endometrium.
IV. An intact endometrium is necessary for implantation of the fertilised ovum.
Which of the statements given above are correct according to the NCERT text?
54.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 54):
Assertion (A): During pregnancy, all events of the menstrual cycle stop and there is no
menstruation.
Reason (R): High levels of progesterone are essential to maintain the endometrium, which is
necessary for implantation of the fertilised ovum.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 54):
Assertion (A): During pregnancy, all events of the menstrual cycle stop and there is no
menstruation.
Reason (R): High levels of progesterone are essential to maintain the endometrium, which is
necessary for implantation of the fertilised ovum.
In the light of the above statements, choose the correct answer:
55.Consider the following statements regarding the termination and cessation of reproductive
cycles in human females (Question 55):
I. In the absence of fertilisation, the corpus luteum degenerates.
II. Disintegration of the endometrium leads to menstruation, marking the start of a new cycle.
III. In human beings, menstrual cycles cease around seventy years of age, which is termed as
menopause.
IV. Cyclic menstruation is an indicator of a normal reproductive phase and extends between
menarche and menopause.
Which of the statements given above are correct according to the NCERT text?
cycles in human females (Question 55):
I. In the absence of fertilisation, the corpus luteum degenerates.
II. Disintegration of the endometrium leads to menstruation, marking the start of a new cycle.
III. In human beings, menstrual cycles cease around seventy years of age, which is termed as
menopause.
IV. Cyclic menstruation is an indicator of a normal reproductive phase and extends between
menarche and menopause.
Which of the statements given above are correct according to the NCERT text?
56.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 56):
Assertion (A): Secretion of gonadotropins (LH and FSH) increases gradually during the
follicular phase.
Reason (R): The gradual increase of LH and FSH stimulates follicular development and
secretion of estrogens by the growing follicles.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 56):
Assertion (A): Secretion of gonadotropins (LH and FSH) increases gradually during the
follicular phase.
Reason (R): The gradual increase of LH and FSH stimulates follicular development and
secretion of estrogens by the growing follicles.
In the light of the above statements, choose the correct answer:
57.Consider the following statements regarding the NCERT guidelines on Menstrual Hygiene
(Question 57):
I. Clean yourself and take bath regularly during menstruation.
II. Change sanitary napkins or homemade pads after every 4–5 hours as per the requirement.
III. Dispose of the used sanitary napkins by throwing them directly into the open area or toilet
drainpipes to prevent home contamination.
IV. After handling the napkin, wash hands with soap.
Which of the statements given above are correct according to the NCERT text?
(Question 57):
I. Clean yourself and take bath regularly during menstruation.
II. Change sanitary napkins or homemade pads after every 4–5 hours as per the requirement.
III. Dispose of the used sanitary napkins by throwing them directly into the open area or toilet
drainpipes to prevent home contamination.
IV. After handling the napkin, wash hands with soap.
Which of the statements given above are correct according to the NCERT text?
58.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 58):
Assertion (A): Progesterone is the primary ovarian steroid hormone that rises during the luteal
phase of the cycle.
Reason (R): Estrogens are secreted by the growing ovarian follicles under the stimulatory action
of gonadotropins.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 58):
Assertion (A): Progesterone is the primary ovarian steroid hormone that rises during the luteal
phase of the cycle.
Reason (R): Estrogens are secreted by the growing ovarian follicles under the stimulatory action
of gonadotropins.
In the light of the above statements, choose the correct answer:
59.Consider the following statements regarding the mid-cycle hormonal events (Question 59):
I. Both LH and FSH attain a peak level in the middle of the cycle (about 14th day).
II. Rapid secretion of LH leading to its maximum level during the mid-cycle is called LH surge.
III. The LH surge induces the regeneration of the endometrial lining of the uterus.
IV. The LH surge induces the rupture of the Graafian follicle to release the secondary oocyte.
Which of the statements given above are correct according to the NCERT text?
I. Both LH and FSH attain a peak level in the middle of the cycle (about 14th day).
II. Rapid secretion of LH leading to its maximum level during the mid-cycle is called LH surge.
III. The LH surge induces the regeneration of the endometrial lining of the uterus.
IV. The LH surge induces the rupture of the Graafian follicle to release the secondary oocyte.
Which of the statements given above are correct according to the NCERT text?
60.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 60):
Assertion (A): The degeneration of the corpus luteum causes disintegration of the endometrium,
marking the beginning of a new menstrual cycle.
Reason (R): High progesterone levels are essential to prevent disintegration and maintain the
endometrium.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 60):
Assertion (A): The degeneration of the corpus luteum causes disintegration of the endometrium,
marking the beginning of a new menstrual cycle.
Reason (R): High progesterone levels are essential to prevent disintegration and maintain the
endometrium.
In the light of the above statements, choose the correct answer:
61.Consider the following statements regarding the transport of gametes and fertilisation
(Question 61):
I. Semen is released by the penis into the vagina during copulation.
II. The motile sperms swim rapidly, pass through the cervix, enter the uterus, and finally reach
the ampullary-isthmic junction of the fallopian tube.
III. Fertilisation can only occur if the ovum and sperms are transported simultaneously to the
ampullary region.
IV. Not all copulations lead to fertilisation and pregnancy due to lack of simultaneous gamete
transport.
Which of the statements given above are correct according to the latest NCERT text?
(Question 61):
I. Semen is released by the penis into the vagina during copulation.
II. The motile sperms swim rapidly, pass through the cervix, enter the uterus, and finally reach
the ampullary-isthmic junction of the fallopian tube.
III. Fertilisation can only occur if the ovum and sperms are transported simultaneously to the
ampullary region.
IV. Not all copulations lead to fertilisation and pregnancy due to lack of simultaneous gamete
transport.
Which of the statements given above are correct according to the latest NCERT text?
62.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 62):
Assertion (A): During human fertilisation, only one sperm is allowed to fuse with and fertilise
the secondary oocyte.
Reason (R): The contact of a sperm with the zona pellucida layer of the ovum induces changes
in the membrane that block the entry of additional sperms.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 62):
Assertion (A): During human fertilisation, only one sperm is allowed to fuse with and fertilise
the secondary oocyte.
Reason (R): The contact of a sperm with the zona pellucida layer of the ovum induces changes
in the membrane that block the entry of additional sperms.
In the light of the above statements, choose the correct answer:
63.Consider the following statements regarding the entry of sperm and subsequent egg
divisions (Question 63):
I. Secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the
zona pellucida and the plasma membrane.
II. The entry of sperm induces the completion of the meiotic division of the primary oocyte.
III. The second meiotic division is unequal and results in the formation of a second polar body
and a haploid ovum (ootid).
IV. The fusion of the haploid nucleus of the sperm and that of the ovum forms a diploid zygote.
Which of the statements given above are correct according to the NCERT text?
divisions (Question 63):
I. Secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the
zona pellucida and the plasma membrane.
II. The entry of sperm induces the completion of the meiotic division of the primary oocyte.
III. The second meiotic division is unequal and results in the formation of a second polar body
and a haploid ovum (ootid).
IV. The fusion of the haploid nucleus of the sperm and that of the ovum forms a diploid zygote.
Which of the statements given above are correct according to the NCERT text?
64.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 64):
Assertion (A): Scientifically, it is correct to say that the sex of the human baby is determined by
the mother and not by the father.
Reason (R): All the haploid gametes (ova) produced by the female have the sex chromosome X,
whereas 50 per cent of male gametes (sperms) carry X and the other 50 per cent carry Y.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 64):
Assertion (A): Scientifically, it is correct to say that the sex of the human baby is determined by
the mother and not by the father.
Reason (R): All the haploid gametes (ova) produced by the female have the sex chromosome X,
whereas 50 per cent of male gametes (sperms) carry X and the other 50 per cent carry Y.
In the light of the above statements, choose the correct answer:
65.Consider the following statements regarding the early development of the human embryo
(Question 65):
I. The mitotic division called cleavage starts as the zygote moves through the isthmus of the
oviduct towards the uterus.
II. Cleavage division forms 2, 4, 8, 16 daughter cells called blastomeres.
III. The embryo with 8 to 16 blastomeres is called a blastocyst.
IV. The morula continues to divide and transforms into a blastocyst as it moves further into the
uterus.
Which of the statements given above are correct according to the NCERT text?
(Question 65):
I. The mitotic division called cleavage starts as the zygote moves through the isthmus of the
oviduct towards the uterus.
II. Cleavage division forms 2, 4, 8, 16 daughter cells called blastomeres.
III. The embryo with 8 to 16 blastomeres is called a blastocyst.
IV. The morula continues to divide and transforms into a blastocyst as it moves further into the
uterus.
Which of the statements given above are correct according to the NCERT text?
66.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 66):
Assertion (A): The division of the zygote as it moves through the isthmus of the oviduct is
referred to as cleavage rather than typical mitosis.
Reason (R): Cleavage starts as the zygote moves through the isthmus and is characterised by
mitotic divisions that form blastomeres.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 66):
Assertion (A): The division of the zygote as it moves through the isthmus of the oviduct is
referred to as cleavage rather than typical mitosis.
Reason (R): Cleavage starts as the zygote moves through the isthmus and is characterised by
mitotic divisions that form blastomeres.
In the light of the above statements, choose the correct answer:
67.Consider the following statements regarding the structural differentiation of the human
blastocyst (Question 67):
I. The blastomeres in the blastocyst are arranged into an outer layer called trophoblast.
II. An inner group of cells attached to the trophoblast is called the inner cell mass.
III. The inner cell mass layer gets attached to the endometrium during implantation.
IV. The trophoblast layer gets differentiated as the embryo proper.
Which of the statements given above are correct according to the NCERT text?
blastocyst (Question 67):
I. The blastomeres in the blastocyst are arranged into an outer layer called trophoblast.
II. An inner group of cells attached to the trophoblast is called the inner cell mass.
III. The inner cell mass layer gets attached to the endometrium during implantation.
IV. The trophoblast layer gets differentiated as the embryo proper.
Which of the statements given above are correct according to the NCERT text?
68.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 68):
Assertion (A): After the trophoblast attaches to the endometrium, the blastocyst becomes
embedded in the uterine wall.
Reason (R): After attachment, the uterine cells divide rapidly and cover the blastocyst, leading
to implantation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 68):
Assertion (A): After the trophoblast attaches to the endometrium, the blastocyst becomes
embedded in the uterine wall.
Reason (R): After attachment, the uterine cells divide rapidly and cover the blastocyst, leading
to implantation.
In the light of the above statements, choose the correct answer:
69.Consider the following statements regarding the ploidy and chromosome counts of cells at
the time of fertilisation (Question 69):
I. The haploid nucleus of the sperm and that of the ovum fuse to form a diploid zygote.
II. The human zygote contains 46 chromosomes.
III. The second polar body, born out of the second meiotic division, is diploid and contains 46
chromosomes.
IV. The blastomeres formed during subsequent cleavages are diploid cells with 46 chromosomes
each.
Which of the statements given above are correct according to the NCERT text?
the time of fertilisation (Question 69):
I. The haploid nucleus of the sperm and that of the ovum fuse to form a diploid zygote.
II. The human zygote contains 46 chromosomes.
III. The second polar body, born out of the second meiotic division, is diploid and contains 46
chromosomes.
IV. The blastomeres formed during subsequent cleavages are diploid cells with 46 chromosomes
each.
Which of the statements given above are correct according to the NCERT text?
70.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 70):
Assertion (A): Cleavage divisions are initiated as the zygote moves through the ampullary
region of the fallopian tube.
Reason (R): The isthmus of the oviduct is the narrow segment that connects the fallopian tube to
the uterus.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 70):
Assertion (A): Cleavage divisions are initiated as the zygote moves through the ampullary
region of the fallopian tube.
Reason (R): The isthmus of the oviduct is the narrow segment that connects the fallopian tube to
the uterus.
In the light of the above statements, choose the correct answer:
71.Consider the following statements regarding the movement of the early human embryo
(Question 71):
I. The morula continues to divide and transforms into a blastocyst as it moves further into the
uterus.
II. The blastocyst is completely formed within the ampulla before migrating to the uterus.
III. Blastomeres in the blastocyst are arranged into an outer trophoblast and an inner cell mass.
IV. Implantation embeds the blastocyst in the endometrium of the uterus, leading to pregnancy.
Which of the statements given above are correct according to the NCERT text?
(Question 71):
I. The morula continues to divide and transforms into a blastocyst as it moves further into the
uterus.
II. The blastocyst is completely formed within the ampulla before migrating to the uterus.
III. Blastomeres in the blastocyst are arranged into an outer trophoblast and an inner cell mass.
IV. Implantation embeds the blastocyst in the endometrium of the uterus, leading to pregnancy.
Which of the statements given above are correct according to the NCERT text?
72.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 72):
Assertion (A): During human fertilisation, multiple sperms are prevented from entering the
oocyte cytoplasm.
Reason (R): The fusion of a sperm with the plasma membrane of the ovum triggers the
immediate dissolution of the zona pellucida.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 72):
Assertion (A): During human fertilisation, multiple sperms are prevented from entering the
oocyte cytoplasm.
Reason (R): The fusion of a sperm with the plasma membrane of the ovum triggers the
immediate dissolution of the zona pellucida.
In the light of the above statements, choose the correct answer:
73.Consider the following statements regarding the structural units formed after implantation
(Question 73):
I. After implantation, finger-like projections appear on the trophoblast called chorionic villi.
II. Chorionic villi are surrounded by the uterine tissue and maternal blood.
III. The chorionic villi and uterine tissue become interdigitated with each other.
IV. The chorionic villi and uterine tissue jointly form a structural and functional unit between
the developing embryo and maternal body called the umbilical cord.
Which of the statements given above are correct according to the NCERT text?
(Question 73):
I. After implantation, finger-like projections appear on the trophoblast called chorionic villi.
II. Chorionic villi are surrounded by the uterine tissue and maternal blood.
III. The chorionic villi and uterine tissue become interdigitated with each other.
IV. The chorionic villi and uterine tissue jointly form a structural and functional unit between
the developing embryo and maternal body called the umbilical cord.
Which of the statements given above are correct according to the NCERT text?
74.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 74):
Assertion (A): The developing embryo is connected to the placenta by a specialized vascular
stalk called the umbilical cord.
Reason (R): The umbilical cord facilitates the transport of nutrients, oxygen, and waste
substances to and from the embryo.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 74):
Assertion (A): The developing embryo is connected to the placenta by a specialized vascular
stalk called the umbilical cord.
Reason (R): The umbilical cord facilitates the transport of nutrients, oxygen, and waste
substances to and from the embryo.
In the light of the above statements, choose the correct answer:
75.Consider the following statements regarding the hormones associated with pregnancy in
human females (Question 75):
I. The placenta acts as an endocrine tissue and produces human chorionic gonadotropin (hCG),
human placental lactogen (hPL), estrogens, and progestogens.
II. In the later phase of pregnancy, a hormone called relaxin is secreted by the placenta.
III. hCG, hPL, and relaxin are hormones produced in women only during pregnancy.
IV. During pregnancy, the levels of other maternal hormones like estrogens, progestogens,
cortisol, prolactin, and thyroxine are increased several-folds in the maternal blood.
Which of the statements given above are correct according to the NCERT text?
human females (Question 75):
I. The placenta acts as an endocrine tissue and produces human chorionic gonadotropin (hCG),
human placental lactogen (hPL), estrogens, and progestogens.
II. In the later phase of pregnancy, a hormone called relaxin is secreted by the placenta.
III. hCG, hPL, and relaxin are hormones produced in women only during pregnancy.
IV. During pregnancy, the levels of other maternal hormones like estrogens, progestogens,
cortisol, prolactin, and thyroxine are increased several-folds in the maternal blood.
Which of the statements given above are correct according to the NCERT text?
76.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 76):
Assertion (A): During pregnancy, levels of maternal blood hormones such as estrogens,
progestogens, cortisol, prolactin, and thyroxine undergo several-fold increases.
Reason (R): Increased production of these maternal hormones is essential for supporting fetal
growth, metabolic changes in the mother, and maintenance of pregnancy.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 76):
Assertion (A): During pregnancy, levels of maternal blood hormones such as estrogens,
progestogens, cortisol, prolactin, and thyroxine undergo several-fold increases.
Reason (R): Increased production of these maternal hormones is essential for supporting fetal
growth, metabolic changes in the mother, and maintenance of pregnancy.
In the light of the above statements, choose the correct answer:
77.Consider the following statements regarding the germ layer differentiation in the human
embryo (Question 77):
I. Immediately after implantation, the inner cell mass differentiates into an outer ectoderm and
an inner endoderm.
II. A mesoderm soon appears between the ectoderm and the endoderm.
III. The ectoderm, endoderm, and mesoderm layers give rise to all tissues and organs in adults.
IV. The trophoblast layer contains certain cells called stem cells which have the potency to give
rise to all the tissues and organs.
Which of the statements given above are correct according to the NCERT text?
embryo (Question 77):
I. Immediately after implantation, the inner cell mass differentiates into an outer ectoderm and
an inner endoderm.
II. A mesoderm soon appears between the ectoderm and the endoderm.
III. The ectoderm, endoderm, and mesoderm layers give rise to all tissues and organs in adults.
IV. The trophoblast layer contains certain cells called stem cells which have the potency to give
rise to all the tissues and organs.
Which of the statements given above are correct according to the NCERT text?
78.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 78):
Assertion (A): The inner cell mass is capable of forming all types of specialized tissues and
organs in the adult human body.
Reason (R): The inner cell mass contains pluripotent stem cells that have the biological potency
to differentiate into any cell lineage.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 78):
Assertion (A): The inner cell mass is capable of forming all types of specialized tissues and
organs in the adult human body.
Reason (R): The inner cell mass contains pluripotent stem cells that have the biological potency
to differentiate into any cell lineage.
In the light of the above statements, choose the correct answer:
79.Consider the following statements regarding the developmental milestones of the human
fetus (Question 79):
I. In human beings, after one month of pregnancy, the embryo’s heart is formed.
II. The first sign of the growing fetus may be noticed by listening to the heart sound carefully
through the stethoscope.
III. By the end of the first month of pregnancy, the fetus develops limbs and digits.
IV. By the end of the second month of pregnancy, major organ systems are fully formed.
Which of the statements given above are correct according to the NCERT text?
fetus (Question 79):
I. In human beings, after one month of pregnancy, the embryo’s heart is formed.
II. The first sign of the growing fetus may be noticed by listening to the heart sound carefully
through the stethoscope.
III. By the end of the first month of pregnancy, the fetus develops limbs and digits.
IV. By the end of the second month of pregnancy, major organ systems are fully formed.
Which of the statements given above are correct according to the NCERT text?
80.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 80):
Assertion (A): By the end of the first trimester (12 weeks of gestation), the major organ systems
of the human fetus are formed.
Reason (R): The limbs and external genital organs are well-developed by the end of 12 weeks of
pregnancy.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 80):
Assertion (A): By the end of the first trimester (12 weeks of gestation), the major organ systems
of the human fetus are formed.
Reason (R): The limbs and external genital organs are well-developed by the end of 12 weeks of
pregnancy.
In the light of the above statements, choose the correct answer:
81.Consider the following statements regarding the developmental milestones of the second
trimester (Question 81):
I. The first movements of the fetus and appearance of hair on the head are usually observed
during the fifth month.
II. By the end of about 24 weeks (end of second trimester), the body is covered with fine hair.
III. Eye-lids separate and eyelashes are formed by the end of 24 weeks.
IV. By the end of the fifth month, eye-lids separate and the body is covered with fine hair.
Which of the statements given above are correct according to the NCERT text?
trimester (Question 81):
I. The first movements of the fetus and appearance of hair on the head are usually observed
during the fifth month.
II. By the end of about 24 weeks (end of second trimester), the body is covered with fine hair.
III. Eye-lids separate and eyelashes are formed by the end of 24 weeks.
IV. By the end of the fifth month, eye-lids separate and the body is covered with fine hair.
Which of the statements given above are correct according to the NCERT text?
82.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 82):
Assertion (A): Listening to the heart sound carefully through a stethoscope is a clinically reliable
first sign of the growing fetus.
Reason (R): The embryo’s heart is the first functional organ to be formed, appearing after one
month of pregnancy.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 82):
Assertion (A): Listening to the heart sound carefully through a stethoscope is a clinically reliable
first sign of the growing fetus.
Reason (R): The embryo’s heart is the first functional organ to be formed, appearing after one
month of pregnancy.
In the light of the above statements, choose the correct answer:
83.Consider the following statements regarding the endocrine status during human gestation
(Question 83):
I. hCG, hPL, and relaxin are the only hormones produced in women during pregnancy.
II. hCG, hPL, and relaxin are produced in women only during pregnancy.
III. The levels of estrogens, progestogens, cortisol, prolactin, and thyroxine are increased
several-folds in the maternal blood during pregnancy.
IV. Elevated maternal thyroxine and prolactin levels are deleterious and must be clinically
suppressed.
Which of the statements given above are correct according to the NCERT text?
(Question 83):
I. hCG, hPL, and relaxin are the only hormones produced in women during pregnancy.
II. hCG, hPL, and relaxin are produced in women only during pregnancy.
III. The levels of estrogens, progestogens, cortisol, prolactin, and thyroxine are increased
several-folds in the maternal blood during pregnancy.
IV. Elevated maternal thyroxine and prolactin levels are deleterious and must be clinically
suppressed.
Which of the statements given above are correct according to the NCERT text?
84.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 84):
Assertion (A): Immediately after implantation, the inner cell mass (embryo) differentiates to
form ectoderm, endoderm, and subsequently mesoderm.
Reason (R): Ectoderm forms the inner layer of the embryo, while endoderm constitutes the
outer boundary during differentiation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 84):
Assertion (A): Immediately after implantation, the inner cell mass (embryo) differentiates to
form ectoderm, endoderm, and subsequently mesoderm.
Reason (R): Ectoderm forms the inner layer of the embryo, while endoderm constitutes the
outer boundary during differentiation.
In the light of the above statements, choose the correct answer:
85.Consider the following statements regarding the initiation of parturition (childbirth)
(Question 85):
I. The average duration of human pregnancy is about 9 months, which is called the gestation
period.
II. Parturition is induced by a complex neuroendocrine mechanism.
III. The signals for parturition originate exclusively from the maternal pituitary gland.
IV. The parturition signals induce mild uterine contractions called the fetal ejection reflex.
Which of the statements given above are correct according to the NCERT text?
(Question 85):
I. The average duration of human pregnancy is about 9 months, which is called the gestation
period.
II. Parturition is induced by a complex neuroendocrine mechanism.
III. The signals for parturition originate exclusively from the maternal pituitary gland.
IV. The parturition signals induce mild uterine contractions called the fetal ejection reflex.
Which of the statements given above are correct according to the NCERT text?
86.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 86):
Assertion (A): During labor, uterine contractions become progressively stronger and more
frequent.
Reason (R): Oxytocin acts on the uterine muscle causing contractions, which in turn stimulates
further secretion of oxytocin from the maternal pituitary.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 86):
Assertion (A): During labor, uterine contractions become progressively stronger and more
frequent.
Reason (R): Oxytocin acts on the uterine muscle causing contractions, which in turn stimulates
further secretion of oxytocin from the maternal pituitary.
In the light of the above statements, choose the correct answer:
87.Consider the following statements regarding the delivery phase of parturition (Question
87):
I. Uterine contractions lead to the expulsion of the baby out of the uterus through the birth
canal.
II. Soon after the infant is delivered, the placenta is also expelled out of the uterus.
III. To induce delivery in cases of weak contractions, doctors inject gonadotropins into the
mother.
IV. The birth canal is formed by the cervical canal along with the vagina.
Which of the statements given above are correct according to the NCERT text?
87):
I. Uterine contractions lead to the expulsion of the baby out of the uterus through the birth
canal.
II. Soon after the infant is delivered, the placenta is also expelled out of the uterus.
III. To induce delivery in cases of weak contractions, doctors inject gonadotropins into the
mother.
IV. The birth canal is formed by the cervical canal along with the vagina.
Which of the statements given above are correct according to the NCERT text?
88.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 88):
Assertion (A): The fetal ejection reflex is the initial trigger that starts the neuroendocrine
cascade of labor.
Reason (R): The fetal ejection reflex is induced directly by physical signals originating from the
maternal ovaries at gestation end.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 88):
Assertion (A): The fetal ejection reflex is the initial trigger that starts the neuroendocrine
cascade of labor.
Reason (R): The fetal ejection reflex is induced directly by physical signals originating from the
maternal ovaries at gestation end.
In the light of the above statements, choose the correct answer:
89.Consider the following statements regarding lactation and colostrum in humans (Question
89):
I. The mammary glands undergo differentiation during pregnancy and start producing milk
towards the end of pregnancy.
II. Lactation is the process of milk production that begins during the first trimester to prepare
for delivery.
III. The milk produced during the initial few days of lactation is called colostrum.
IV. Colostrum contains several antibodies absolutely essential to develop resistance for the new-
born.
Which of the statements given above are correct according to the NCERT text?
89):
I. The mammary glands undergo differentiation during pregnancy and start producing milk
towards the end of pregnancy.
II. Lactation is the process of milk production that begins during the first trimester to prepare
for delivery.
III. The milk produced during the initial few days of lactation is called colostrum.
IV. Colostrum contains several antibodies absolutely essential to develop resistance for the new-
born.
Which of the statements given above are correct according to the NCERT text?
90.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 90):
Assertion (A): Breast-feeding during the initial period of infant growth is strongly
recommended by doctors for bringing up a healthy baby.
Reason (R): Colostrum contains several antibodies absolutely essential to develop resistance for
the new-born babies.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 90):
Assertion (A): Breast-feeding during the initial period of infant growth is strongly
recommended by doctors for bringing up a healthy baby.
Reason (R): Colostrum contains several antibodies absolutely essential to develop resistance for
the new-born babies.
In the light of the above statements, choose the correct answer:
91.Consider the following statements combining details from the Chapter Summary and
Exercises (Question 91):
I. Parturition is induced by a complex neuroendocrine mechanism involving cortisol, estrogens,
and oxytocin.
II. Leydig cells are found in the ovaries and synthesise androgens.
III. The presence of X or Y chromosome in the fertilising sperm determines the sex of the
embryo.
IV. The new-born baby is fed milk by the mother (lactation) during the initial few months of
growth.
Which of the statements given above are correct according to the NCERT text?
Exercises (Question 91):
I. Parturition is induced by a complex neuroendocrine mechanism involving cortisol, estrogens,
and oxytocin.
II. Leydig cells are found in the ovaries and synthesise androgens.
III. The presence of X or Y chromosome in the fertilising sperm determines the sex of the
embryo.
IV. The new-born baby is fed milk by the mother (lactation) during the initial few months of
growth.
Which of the statements given above are correct according to the NCERT text?
92.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 92):
Assertion (A): The placenta acts as a temporary endocrine tissue that supports pregnancy by
secreting specialized hormones.
Reason (R): The placenta secretes luteinising hormone (LH) to prevent the degeneration of the
corpus luteum during early gestation.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 92):
Assertion (A): The placenta acts as a temporary endocrine tissue that supports pregnancy by
secreting specialized hormones.
Reason (R): The placenta secretes luteinising hormone (LH) to prevent the degeneration of the
corpus luteum during early gestation.
In the light of the above statements, choose the correct answer:
93.Consider the following statements based on the conceptual review questions in the NCERT
Exercises (Question 93):
I. Androgens are produced by Sertoli cells.
II. Spermatozoa get nutrition from Sertoli cells.
III. Leydig cells synthesise androgens.
IV. Oogenesis takes place in the corpus luteum.
Which of the statements given above are correct according to the NCERT Exercises?
Exercises (Question 93):
I. Androgens are produced by Sertoli cells.
II. Spermatozoa get nutrition from Sertoli cells.
III. Leydig cells synthesise androgens.
IV. Oogenesis takes place in the corpus luteum.
Which of the statements given above are correct according to the NCERT Exercises?
94.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 94):
Assertion (A): The presence or absence of the hymen is not a reliable indicator of virginity or
sexual experience.
Reason (R): The opening of the vagina is often covered partially by a membrane called hymen,
which can be torn by sudden jolts, tampons, or sports, or may persist after coitus.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 94):
Assertion (A): The presence or absence of the hymen is not a reliable indicator of virginity or
sexual experience.
Reason (R): The opening of the vagina is often covered partially by a membrane called hymen,
which can be torn by sudden jolts, tampons, or sports, or may persist after coitus.
In the light of the above statements, choose the correct answer:
95.Consider the following statements regarding the summary facts of gametogenesis and
reproduction (Question 95):
I. Spermatogenesis results in the formation of haploid sperms.
II. Oogenesis results in the formation of a diploid secondary oocyte.
III. The presence of X or Y chromosome in the sperm determines the sex of the embryo.
IV. The zygote undergoes repeated mitotic division to form a blastocyst.
Which of the statements given above are correct according to the Chapter Summary?
reproduction (Question 95):
I. Spermatogenesis results in the formation of haploid sperms.
II. Oogenesis results in the formation of a diploid secondary oocyte.
III. The presence of X or Y chromosome in the sperm determines the sex of the embryo.
IV. The zygote undergoes repeated mitotic division to form a blastocyst.
Which of the statements given above are correct according to the Chapter Summary?
96.Given below are two statements, one is labelled as Assertion (A) and the other is labelled as
Reason (R) (Question 96):
Assertion (A): The placenta is expelled out of the uterus soon after the infant is delivered.
Reason (R): High progesterone levels at labor onset stimulate the rapid mitotic proliferation of
placental cells to detach from the endometrium.
In the light of the above statements, choose the correct answer:
Reason (R) (Question 96):
Assertion (A): The placenta is expelled out of the uterus soon after the infant is delivered.
Reason (R): High progesterone levels at labor onset stimulate the rapid mitotic proliferation of
placental cells to detach from the endometrium.
In the light of the above statements, choose the correct answer:
Answer Key
11
21
31
42
51
61
74
82
93
104
113
122
131
143
154
161
173
182
193
204
213
222
233
243
254
264
272
282
293
304
314
321
333
341
353
364
374
381
393
404
414
422
432
441
451
462
474
481
491
503
514
522
532
542
554
562
573
581
594
601
612
622
631
644
654
661
672
684
693
701
712
722
732
743
752
764
774
784
793
801
811
824
831
843
852
862
872
883
891
903
911
921
932
944
951
964