Q1. The embryo with 8 to 16 blastomeres is called a:
Correct Answer: (b)
The embryo with 8 to 16 daughter cells is called a morula. It is a solid ball of cells formed by cleavage divisions of the zygote.
Q2. Which of the following is correct? (i) Sperm formation continues in old men. (ii) Ovum formation ceases around age 50 in women. (iii) Humans are sexually reproducing and viviparous.
Correct Answer: (a)
Spermatogenesis continues throughout life; oogenesis ceases at menopause (~50 years); humans are sexually reproducing and viviparous.
Q3. The signals for parturition originate from:
Correct Answer: (c)
The signals for parturition originate from the fully developed foetus and the placenta. This triggers a neuroendocrine cascade leading to uterine contractions.
Q4. Regarding the female reproductive system, which are true? (i) Ovaries are primary female sex organs. (ii) Ovarian stroma is divided into cortex and medulla. (iii) Fallopian tubes are 10-12 cm long.
Correct Answer: (a)
All points are standard anatomical facts: ovaries are primary sex organs; stroma has cortex and medulla; fallopian tubes are about 10-12 cm long.
Q5. Match the embryonic milestones:
Month
Event
1st Month
(I) First movements
2nd Month
(II) Heart is formed
5th Month
(III) Limbs and digits
Correct Answer: (a)
In 1st month heart develops; 2nd month limbs and digits appear; 5th month first movements (quickening) are felt.
Q6. Which are correct regarding lactation? (i) Mammary glands undergo differentiation during pregnancy. (ii) Colostrum is rich in antibodies. (iii) Breast-feeding is recommended for infant health.
Correct Answer: (a)
Mammary glands develop under hormonal influence; colostrum provides antibodies; breastfeeding is recommended for nutrition and immunity.
Q7. Match the Following for Chromosomes:
Cell
Chromosome Count
A. Human Somatic Cell
(I) 46
B. Human Gamete
(II) 23
Correct Answer: (a)
Somatic cells are diploid (46 chromosomes); gametes are haploid (23 chromosomes).
Q8. Assertion: The human male ejaculates 200 to 300 million sperms during a coitus.
Reason: For normal fertility, at least 40 per cent of these must show vigorous motility.
Correct Answer: (a)
Both are physiological requirements for fertility, but motility requirement doesn't explain the number ejaculated. The high number is needed to overcome barriers in the female tract, while motility is a quality requirement.
Q9. The process of transformation of spermatids into spermatozoa is:
Correct Answer: (b)
The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis. It involves morphological changes including formation of acrosome and tail.
Q10. Which of the following phylum/group characteristics is being described? (i) They are sexually reproducing and viviparous. (ii) Male and female reproductive systems are distinct. (iii) Fertilisation and development are internal.
Correct Answer: (c)
Humans are sexually reproducing, viviparous, and have internal fertilisation. These characteristics match mammals, and humans are mammals.
Q11. Identify the correct statements regarding the male reproductive system: (i) Testes are located in the scrotum. (ii) Scrotum maintains a temperature lower than body temperature. (iii) Each testis has 250 seminiferous tubules.
Correct Answer: (a)
Testes are in the scrotum (i true); scrotum maintains lower temperature (ii true); each testis has 250 lobules, not seminiferous tubules (iii false). So (i) and (ii) are correct.
Q12. The male external genitalia is the:
Correct Answer: (c)
The penis is the male external genitalia. It is copulatory organ that delivers sperms into the female reproductive tract during insemination.
Q13. Match the uterine layers with descriptions:
Column-I
Column-II
A. Perimetrium
(I) Inner glandular layer
B. Myometrium
(II) Middle thick muscle
C. Endometrium
(III) External thin membrane
Correct Answer: (a)
Perimetrium is the outer thin layer; myometrium is thick muscle; endometrium is the inner glandular layer.
Q14. Assertion: The morula continues to divide and transforms into a blastocyst.
Reason: The blastocyst moves further into the uterus.
Correct Answer: (a)
Both are sequential events in embryonic passage, but the transformation into blastocyst is due to fluid accumulation and cell differentiation, not because it moves into the uterus.
Q15. The milk produced during the initial few days of lactation is called:
Correct Answer: (b)
The milk produced during the initial few days of lactation is called colostrum. It is rich in antibodies (IgA) and provides passive immunity to the newborn.
Q16. The middle thick muscular layer of the uterus is called:
Correct Answer: (c)
The middle thick layer of smooth muscle is the myometrium. It is responsible for strong uterine contractions during childbirth and menstrual expulsion.
Q17. Assertion: The presence of hymen is not a reliable indicator of virginity.
Reason: The hymen can be broken by a sudden fall, jolt, or active participation in sports.
Correct Answer: (a)
Physical activities other than coitus can rupture the hymen. Therefore, its presence or absence cannot be used as a definitive marker of sexual experience.
Q18. The temperature of the testes is maintained at:
Correct Answer: (b)
The scrotum helps in maintaining the low temperature of the testes (2–2.5° C lower than the normal internal body temperature). This lower temperature is essential for proper spermatogenesis.
Q19. Assertion: Fertilisation restores the diploid phase.
Reason: Haploid gametes fuse to form a diploid zygote.
Correct Answer: (a)
Fusion of n + n = 2n. This restores the diploid chromosome number in the zygote, which is essential for normal development.
Q20. Transfer of sperms into the female genital tract is called:
Correct Answer: (c)
Transfer of sperms into the female genital tract is termed insemination. It is a prerequisite for fertilisation but does not guarantee it.
Q21. Assertion: The middle piece of the sperm is called the powerhouse of the sperm.
Reason: It possesses numerous mitochondria which produce energy for the movement of the tail.
Correct Answer: (a)
Mitochondria in the middle piece provide the energy for motility. This ATP is essential for the flagellar movement that propels the sperm through the female reproductive tract.
Q22. The process of formation of gametes is called:
Correct Answer: (b)
The reproductive events in humans include formation of gametes (gametogenesis). This is the first step in sexual reproduction, where specialized cells (gametes) are produced in gonads.
Q23. Assertion: The testes are situated outside the abdominal cavity within a pouch called scrotum.
Reason: Scrotum helps in maintaining the low temperature of the testes necessary for spermatogenesis.
Correct Answer: (a)
Spermatogenesis requires a temperature lower than the normal body temperature. The scrotum provides this by keeping the testes outside the body cavity, and its muscular adjustments help regulate temperature.
Q24. Which of the following are correct regarding spermatogenesis? (i) Initiated at puberty due to increase in GnRH. (ii) Primary spermatocytes are haploid. (iii) LH acts on Leydig cells to stimulate androgens.
Correct Answer: (a)
Statement (ii) is incorrect; primary spermatocytes are diploid (2n). (i) and (iii) are correct: GnRH triggers puberty and LH stimulates Leydig cells.
Q25. Match the embryonic layers with their types:
Column-I (Layer)
Column-II (Type)
A. Ectoderm
(I) Inner layer
B. Mesoderm
(II) Outer layer
C. Endoderm
(III) Middle layer
Correct Answer: (a)
Standard embryonic layer positions: ectoderm is outermost, mesoderm in middle, endoderm innermost.
Q26. Regarding the 'Testis' structure: (i) Oval in shape. (ii) 4-5 cm length, 2-3 cm width. (iii) Covered by a dense covering.
Correct Answer: (a)
Testis is oval, about 4-5 cm long and 2-3 cm wide, and is covered by a fibrous capsule (tunica albuginea).
Q27. Match the following for fertilization barriers:
Layer
Location
A. Zona pellucida
(I) Outer layer of cells
B. Corona radiata
(II) Membrane directly surrounding ovum
Correct Answer: (a)
Zona pellucida is the glycoprotein layer directly surrounding the ovum; corona radiata is the outer layer of follicular cells.
Q28. Assertion: Only one sperm can fertilise an ovum.
Reason: During fertilisation, a sperm induces changes in the zona pellucida that block the entry of additional sperms.
Correct Answer: (a)
The block to polyspermy ensures a diploid zygote. Once a sperm fuses with the oolemma, cortical granules release enzymes that harden the zona pellucida, preventing other sperm from entering.
Q29. Which are correct for 'Spermiation'? (i) Release of sperms from Sertoli cells. (ii) Occurs after spermiogenesis. (iii) Results in release from seminiferous tubules.
Correct Answer: (a)
Spermiation is release from Sertoli cells; it follows spermiogenesis; the sperms are then released into the tubule lumen.
Q30. Match the male reproductive structures in Column-I with their descriptions in Column-II:
Column-I (Structure)
Column-II (Description)
A. Testicular lobules
(I) One to three highly coiled tubes
B. Seminiferous tubules
(II) 250 compartments per testis
C. Leydig cells
(III) Present in intertubular spaces
D. Sertoli cells
(IV) Provide nutrition to germ cells
Correct Answer: (a)
Based on Section 2.1 descriptions: each testis has 250 lobules; each lobule contains 1-3 seminiferous tubules; Leydig cells are in interstitial spaces; Sertoli cells provide nutrition.
Q31. Match the male accessory ducts:
Column-I
Column-II
A. Rete testis
(I) Opens into epididymis
B. Vasa efferentia
(II) Network of tubules
C. Epididymis
(III) Leads to vas deferens
Correct Answer: (a)
Rete testis is a network; vasa efferentia connect rete to epididymis; epididymis stores sperms and leads to vas deferens.
Q32. The structure that provides a functional link between the foetus and maternal body is:
Correct Answer: (b)
The chorionic villi and uterine tissue become interdigitated... and jointly form a structural and functional unit... called placenta. It facilitates nutrient, gas, and waste exchange.
Q33. Match the following for Male Glands:
Gland
Count
A. Seminal vesicle
(I) Paired
B. Prostate
(II) Paired
C. Bulbourethral
(III) Single (Unpaired)
Correct Answer: (a)
Seminal vesicles are paired; prostate is single; bulbourethral glands are paired.
Q34. Oogenesis is initiated during:
Correct Answer: (c)
Oogenesis is initiated during the embryonic development stage when a couple of million gamete mother cells are formed within each fetal ovary. No new oogonia are formed after birth.
Q35. Select the correct statements for oogenesis: (i) Initiated during embryonic development. (ii) Tertiary follicle has a fluid-filled cavity (antrum). (iii) Graafian follicle releases a secondary oocyte.
Correct Answer: (a)
All points are characteristically true: oogenesis starts in fetus; tertiary follicle has antrum; Graafian follicle releases secondary oocyte at ovulation.
Q36. Regarding the menstrual cycle: (i) Menarche is the first menstruation. (ii) LH surge induces ovulation on the 14th day. (iii) Progesterone is secreted by the corpus luteum.
Correct Answer: (a)
These are the standard hormonal and temporal markers: menarche is first menstruation; LH surge causes ovulation around day 14; corpus luteum secretes progesterone.
Q37. Match the mammary gland parts in sequence (Internal to External):
Step
Structure
1st
Alveoli
2nd
Mammary tubules/ducts
3rd
Mammary ampulla
4th
Lactiferous duct
Correct Answer: (a)
Pathway of milk as described: alveoli → mammary tubules → mammary ampulla → lactiferous duct → nipple. So the sequence given is correct.
Q38. Identify the correct statements for fertilisation: (i) Takes place in the ampullary-isthmic junction (or ampulla). (ii) Only one sperm can fertilise the ovum. (iii) Acrosome secretions help the sperm enter the ovum.
Correct Answer: (a)
Fertilisation occurs in ampulla; only one sperm enters due to block to polyspermy; acrosome enzymes help penetrate the egg's layers.
Q39. Assertion: Relaxin is a hormone produced only during pregnancy.
Reason: It is secreted by the ovary in the later phase of pregnancy.
Correct Answer: (b)
Both are true, but the site of secretion (ovary) does not explain why it is only produced during pregnancy. Relaxin is also produced by the placenta and helps soften the cervix and pelvic ligaments for childbirth.
Q40. Regarding the structure of sperm: (i) Middle piece contains mitochondria for energy. (ii) Head contains an elongated haploid nucleus. (iii) Tail facilitates sperm motility.
Correct Answer: (a)
Sperm structure is well-characterised: middle piece has mitochondria; head has haploid nucleus; tail provides motility.
Q41. Which cells provide nutrition to the male germ cells?
Correct Answer: (c)
Sertoli cells provide nutrition to the germ cells. They also support the developing spermatocytes and spermatids, and secrete factors essential for spermatogenesis.
Q42. Assertion: The LH surge induces the rupture of the Graafian follicle.
Reason: LH and FSH reach a peak level in the middle of the cycle.
Correct Answer: (a)
The peak level of LH (surge) is the direct trigger for ovulation. The sudden rise of LH causes the follicle to swell and rupture, releasing the secondary oocyte.
Q43. Match the cells with their ploidy:
Column-I
Column-II
A. Spermatogonia
(I) Haploid (n)
B. Primary spermatocytes
(II) Diploid (2n)
C. Spermatids
(III) Diploid (2n)
Correct Answer: (a)
Note: Both Spermatogonia and Primary Spermatocytes are 2n; Spermatids are n. The mapping assigns A->III (diploid), B->II (diploid), C->I (haploid).
Q44. Fertilisation in humans usually takes place in the:
Correct Answer: (c)
The ovum released by the ovary is also transported to the ampullary region where fertilisation takes place. This is the widest part of the oviduct and is ideal for sperm-egg fusion.
Q45. Identify correct features of 'Relaxin': (i) Peptide hormone. (ii) Produced in later phase of pregnancy. (iii) Secreted by the ovary.
Correct Answer: (a)
Relaxin is a peptide hormone produced by the corpus luteum (ovary) and placenta during pregnancy, especially in later stages.
Q46. Assertion: Oogenesis is initiated during the embryonic development stage.
Reason: No more oogonia are formed and added after birth.
Correct Answer: (a)
The total number of potential eggs is determined before birth. Oogonia multiply by mitosis in the fetal ovary and then enter meiosis I, but stop at prophase I. After birth, no new oogonia are generated, so the pool is fixed.
Q47. Assertion: Primary follicles contain a primary oocyte.
Reason: A large number of these follicles degenerate from birth to puberty.
Correct Answer: (a)
Both are true structural/temporal facts about the ovary, but the degeneration (atresia) does not explain why primary follicles contain a primary oocyte. That is simply their developmental stage.
Q48. Match the follicle stage with features:
Column-I
Column-II
A. Primary follicle
(I) Antrum present
B. Secondary follicle
(II) Primary oocyte + granulosa
C. Tertiary follicle
(III) More granulosa + new theca
Correct Answer: (a)
Primary follicle: primary oocyte surrounded by granulosa; secondary: more layers of granulosa and theca; tertiary: antrum appears.
Q49. Assertion: Colostrum is absolutely essential for newborn babies.
Reason: It contains several antibodies to develop resistance.
Correct Answer: (a)
Passive immunity is provided by antibodies in colostrum. Newborns have immature immune systems, so the antibodies from colostrum protect them against infections in the first few days.
Q50. Which are correct for the 'Leydig cells'? (i) Found in interstitial spaces. (ii) Secrete androgens. (iii) Found inside seminiferous tubules.
Correct Answer: (a)
Leydig cells are in interstitial spaces outside seminiferous tubules; they secrete androgens. (iii) is false because they are not inside tubules.
Q51. Identify true statements for 'Secondary Oocyte': (i) Retains bulk of nutrient-rich cytoplasm. (ii) Formed after meiosis I. (iii) Surrounded by zona pellucida.
Correct Answer: (a)
Secondary oocyte gets most cytoplasm; it is produced after meiosis I; it is surrounded by zona pellucida.
Q52. Match the hormones with their source glands:
Column-I (Hormone)
Column-II (Source)
A. GnRH
(I) Maternal Pituitary
B. LH & FSH
(II) Hypothalamus
C. Oxytocin
(III) Anterior Pituitary
D. Relaxin
(IV) Ovary (Placenta context)
Correct Answer: (a)
GnRH from hypothalamus; LH/FSH from anterior pituitary; oxytocin from maternal pituitary (posterior); relaxin from ovary/placenta during pregnancy.
Q53. Match the female reproductive regions in Column-I with their features in Column-II:
Column-I (Region)
Column-II (Feature)
A. Infundibulum
(I) Narrow lumen joining uterus
B. Fimbriae
(II) Wider part of oviduct
C. Ampulla
(III) Funnel-shaped part
D. Isthmus
(IV) Finger-like projections
Correct Answer: (a)
Infundibulum is funnel-shaped; fimbriae are finger-like projections; ampulla is the wider part; isthmus is the narrow part near the uterus.
Q54. Assertion: Mammary glands are integrated with the female reproductive system.
Reason: They support the processes of child care.
Correct Answer: (a)
Functional integration supports the offspring after birth. Mammary glands undergo development during pregnancy and produce milk (lactation) to nourish the newborn, thus completing the reproductive cycle.
Q55. Seminal plasma is rich in:
Correct Answer: (b)
Secretions of male accessory glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes. Fructose provides energy for sperm motility, while enzymes help in liquefaction of semen.
Q56. Match the terms with their definitions:
Column-I
Column-II
A. Insemination
(I) Release of sperms from tubules
B. Spermiation
(II) Transfer of sperms to female tract
C. Ovulation
(III) Release of ovum from ovary
Correct Answer: (a)
Insemination: transfer of sperms; spermiation: release from Sertoli cells into tubule lumen; ovulation: release of ovum from ovary.
Q57. The Leydig cells secrete testicular hormones called:
Correct Answer: (b)
Leydig cells synthesise and secrete testicular hormones called androgens, mainly testosterone. These hormones are responsible for male secondary sex characteristics and spermatogenesis.
Q58. Which are correct for 'Blastocyst' implantation? (i) Trophoblast attaches to endometrium. (ii) Inner cell mass differentiates into embryo. (iii) Uterine cells divide rapidly to cover blastocyst.
Correct Answer: (a)
Trophoblast adheres to endometrium; inner cell mass forms embryo; uterine cells proliferate to embed the blastocyst.
Q59. Assertion: Cleavage refers to the mitotic divisions of the zygote.
Reason: It results in daughter cells called blastomeres.
Correct Answer: (b)
Both are true, but the formation of blastomeres is the result, not the 'reason' for the division being called cleavage. Cleavage is defined as rapid mitotic division without growth.
Q60. Which hormone acts on the Leydig cells to stimulate secretion of androgens?
Correct Answer: (c)
LH acts at the Leydig cells and stimulates synthesis and secretion of androgens. This is essential for maintaining spermatogenesis and male secondary sexual characteristics.
Q61. In spermatogenesis, the first meiotic division leads to the formation of:
Correct Answer: (c)
A primary spermatocyte completes the first meiotic division leading to formation of two equal, haploid secondary spermatocytes. This is the reductional division.
Q62. Correct statements for 'Corpus Luteum': (i) Formed from ruptured Graafian follicle. (ii) Secretes large amounts of progesterone. (iii) Degenerates if fertilisation does not occur.
Correct Answer: (a)
Corpus luteum forms after ovulation; it secretes progesterone; if no fertilisation, it degenerates into corpus albicans.
Q63. Regarding 'Mammary Lobes': (i) 15-20 per breast. (ii) Contain clusters of cells called alveoli. (iii) Alveoli secrete milk.
Correct Answer: (a)
Each breast has 15-20 lobes; lobes contain alveoli; alveoli are the milk-secreting units.
Q64. The first menstruation begins at puberty and is called:
Correct Answer: (b)
The first menstruation begins at puberty and is called menarche. It marks the beginning of the reproductive phase in females.
Q65. Match the phases of the menstrual cycle with events:
Column-I (Phase)
Column-II (Event)
A. Menstrual phase
(I) Regeneration of endometrium
B. Follicular phase
(II) Formation of corpus luteum
C. Luteal phase
(III) Breakdown of endometrium
Correct Answer: (a)
Menstrual phase: shedding of endometrium; follicular phase: regeneration and growth of follicles; luteal phase: corpus luteum formation.
Q66. Which of the following is correct? (i) Fertilisation is the fusion of sperm and ovum. (ii) Zygote is diploid. (iii) Insemination leads to fertilisation.
Correct Answer: (b)
Fertilisation is fusion of gametes, producing a diploid zygote. Insemination is the transfer of sperms, but fertilisation is not guaranteed; it only occurs if sperm meets ovum under suitable conditions.
Q67. Each testis has about ______ compartments called testicular lobules.
Correct Answer: (b)
Each testis has about 250 compartments called testicular lobules. Each lobule contains one to three highly coiled seminiferous tubules where spermatogenesis occurs.
Q68. Select correct statements for 'Menopause': (i) Cessation of menstrual cycles. (ii) Occurs around 50 years of age. (iii) Indicator of normal reproductive phase.
Correct Answer: (a)
Menopause is the end of menstruation, around age 50. It is not an indicator of normal reproductive phase; cyclic menstruation indicates that. So (i) and (ii) correct.
Q69. Assertion: Foetal ejection reflex triggers the release of oxytocin.
Reason: Oxytocin is released from the maternal pituitary.
Correct Answer: (a)
The reflex is the trigger, and the pituitary is the source. However, the reason does not explain why the reflex triggers release; it only states where oxytocin is released from.
Q70. Assertion: Gastric inhibitory peptide (GIP) inhibits gastric secretion.
Reason: GIP is a hormone of the gastrointestinal tract.
Correct Answer: (a)
Function vs classification. GIP indeed inhibits gastric secretion, and it is a GI hormone. However, being a GI hormone does not explain its inhibitory action on gastric secretion; its specific effect is due to its receptor interactions.
Q71. Assertion: Not all copulations lead to fertilisation and pregnancy.
Reason: Fertilisation can only occur if ovum and sperms are transported simultaneously to the ampullary region.
Correct Answer: (a)
The timing and location must match for successful fusion. The ovum is viable for only 24 hours after ovulation, and sperms must be present in the ampulla during that window.
Q72. Match the following for Female Genitalia:
Part
Feature
A. Mons pubis
(I) Fleshy folds of tissue
B. Labia majora
(II) Tiny finger-like structure
C. Clitoris
(III) Cushion of fatty tissue
Correct Answer: (a)
Mons pubis is a fatty cushion; labia majora are fleshy folds; clitoris is a small erectile structure.
Q73. Match the sperm structures with their contents:
Column-I
Column-II
A. Head
(I) Mitochondria
B. Middle piece
(II) Haploid nucleus
C. Acrosome
(III) Enzymes for fertilisation
Correct Answer: (a)
Head contains haploid nucleus; middle piece has mitochondria; acrosome has enzymes for penetration.
Q74. Assertion: The lack of menstruation may be indicative of pregnancy.
Reason: Menstruation only occurs if the released ovum is not fertilised.
Correct Answer: (a)
Fertilisation maintains the corpus luteum and progesterone, preventing the breakdown of the endometrium. If no fertilisation, progesterone level drops, leading to menstruation.
Q75. Which hormone is responsible for strong uterine contractions during childbirth?
Correct Answer: (b)
Oxytocin acts on the uterine muscle and causes stronger uterine contractions. It is released from the maternal pituitary in response to the foetal ejection reflex.
Q76. Which hormone is secreted only during pregnancy in women?
Correct Answer: (c)
hCG, hPL and relaxin are produced in women only during pregnancy. hCG (human chorionic gonadotropin) is secreted by the placenta and maintains the corpus luteum.
Q77. Regarding the placenta: (i) It supplies oxygen and nutrients to the embryo. (ii) It removes carbon dioxide and waste. (iii) It secretes hCG, hPL, and estrogens.
Q78. The finger-like projections of the infundibulum are called:
Correct Answer: (b)
The edges of the infundibulum possess finger-like projections called fimbriae. They help in sweeping the ovum into the fallopian tube after ovulation.
Q79. The cap-like structure at the anterior portion of the sperm head is the:
Correct Answer: (b)
The anterior portion of the sperm head is covered by a cap-like structure, acrosome. It contains hydrolytic enzymes that help the sperm penetrate the egg's layers during fertilisation.
Q80. Rapid secretion of LH leading to its maximum level during the mid-cycle is called:
Correct Answer: (a)
Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces rupture of Graafian follicle and release of ovum (ovulation).
Q81. The stroma of the ovary is divided into two zones:
Correct Answer: (b)
The ovarian stroma is divided into two zones – a peripheral cortex and an inner medulla. The cortex contains ovarian follicles in various stages of development, while medulla has blood vessels and nerves.
Q82. Assertion: The sex of the baby is determined by the mother.
Reason: Humans females have XY sex chromosomes.
Correct Answer: (a)
Sex is determined by the father (X or Y sperm); females are XX. The mother always contributes an X chromosome; the father's sperm carries either X (resulting in female) or Y (resulting in male).
Q83. Assertion: Implantation leads to pregnancy.
Reason: The blastocyst becomes embedded in the endometrium of the uterus.
Correct Answer: (a)
Embedding of the blastocyst is the definition of implantation. This is the critical step that establishes pregnancy, as it allows the embryo to receive nutrients from the mother.
Q84. Identify the correct phylum/group being described? (i) They produce 2500 to 3000 ova at a time (Not humans). (ii) No functional connection between ovaries and kidneys (Human).
Correct Answer: (d)
The statements are contradictory: (i) describes a non-human (e.g., frogs) and (ii) describes humans. No single group fits both, so 'None' is the correct choice.
Q85. Assertion: Secondary spermatocytes are haploid.
Reason: They are formed after the first meiotic division of diploid primary spermatocytes.
Correct Answer: (a)
Meiosis I is the reduction division, reducing the chromosome number from diploid (2n) to haploid (n). Thus secondary spermatocytes are haploid.
Q86. Match the following for parturition:
Term
Meaning
A. Parturition
(I) Childbirth
B. Gestation period
(II) Average duration of pregnancy
Correct Answer: (a)
Parturition is the process of childbirth; gestation period is the duration of pregnancy (about 280 days/40 weeks).
Q87. The fluid-filled cavity characteristic of a tertiary follicle is the:
Correct Answer: (b)
The secondary follicle soon transforms into a tertiary follicle which is characterised by a fluid filled cavity called antrum. This fluid provides nourishment to the developing oocyte.
Q88. The glandular tissue of each breast is divided into 15-20:
Correct Answer: (b)
The glandular tissue of each breast is divided into 15-20 mammary lobes. Each lobe contains clusters of alveoli which secrete milk.
Q89. The sex of the embryo is determined by the:
Correct Answer: (b)
Scientifically it is correct to say that the sex of the baby is determined by the father and not by the mother (due to X or Y chromosome in sperm). The mother contributes an X chromosome, while the father contributes either X or Y.
Q90. Assertion: The corpus luteum secretes large amounts of progesterone.
Reason: Progesterone is essential for the maintenance of the endometrium.
Correct Answer: (a)
Both are true facts, but the necessity for the endometrium doesn't explain why the corpus luteum is the source. The corpus luteum is formed from the ruptured follicle and its main function is to secrete progesterone to sustain the uterine lining.
Q91. Assertion: Male germ cells undergo meiotic divisions to form sperms.
Reason: Sertoli cells provide nutrition to the germ cells.
Correct Answer: (b)
Both are true facts about seminiferous tubules, but the nutrition provided by Sertoli cells is not the reason why germ cells undergo meiosis. Meiosis is required for reducing chromosome number, not for nutrition.
Q92. The funnel-shaped part of the fallopian tube closer to the ovary is the:
Correct Answer: (c)
The part closer to the ovary is the funnel-shaped infundibulum. It opens into the peritoneal cavity and collects the ovum released during ovulation.
Q93. Match the placental hormones with their functions:
Column-I
Column-II
A. hCG & hPL
(I) Pregnancy maintenance
B. Progestogens
(II) Support fetal growth
C. Relaxin
(III) Facilitate parturition
Correct Answer: (a)
hCG and hPL support fetal growth; progestogens maintain pregnancy; relaxin prepares for parturition by softening cervix and ligaments.
Q94. Assertion: Placenta acts as an endocrine tissue.
Reason: It produces several hormones like hCG, hPL, estrogens, and progestogens.
Correct Answer: (a)
Hormone production is the defining characteristic of endocrine tissue. The placenta secretes multiple hormones that are essential for maintaining pregnancy, supporting fetal growth, and preparing for childbirth.
Q95. Which statements regarding embryonic development are true? (i) Morula has 8-16 blastomeres. (ii) Implantation occurs at the blastocyst stage. (iii) Trophoblast is the inner layer of cells in the blastocyst.
Correct Answer: (a)
Morula has 8-16 cells; implantation occurs at blastocyst stage; trophoblast is the outer layer, not inner (inner is inner cell mass). So (i) and (ii) correct.
Correct Answer: (a)
Both statements are accurate: hCG, hPL, relaxin are pregnancy-specific; others increase in concentration during pregnancy.
Q97. Select the correct statements for parturition: (i) Induced by a complex neuroendocrine mechanism. (ii) Foetal ejection reflex triggers oxytocin release. (iii) Gestation period in humans is about 9 months.
Correct Answer: (a)
Parturition is a complex neuroendocrine event; foetal ejection reflex stimulates oxytocin; gestation is about 280 days (9 months).
Q98. Which layer of the uterus undergoes cyclical changes during the menstrual cycle?
Correct Answer: (c)
The endometrium undergoes cyclical changes during the menstrual cycle. It thickens in response to hormones and is shed if fertilisation does not occur.
Q99. Regarding 'Stem Cells': (i) Present in the inner cell mass. (ii) Have potency to give rise to all tissues/organs. (iii) Only found in adults.
Correct Answer: (a)
Stem cells are in inner cell mass; they are pluripotent; they are also found in embryos, not only adults. So (i) and (ii) correct.
Q100. Assertion: Spermatogonia are diploid.
Reason: They are gamete mother cells present on the inside wall of seminiferous tubules.
Correct Answer: (a)
Being mother cells doesn't explain ploidy, though both are true. Spermatogonia are diploid because they undergo mitotic divisions; their location does not determine chromosome number.