Covers NCERT Class 12 Biology, Chapter "Human Reproduction" — reproductive anatomy, gametogenesis, the menstrual cycle, fertilisation, pregnancy and parturition. Among the single most heavily tested chapters in NEET Biology, most years.
Spermatogenesis & oogenesis hormonal control (FSH, LH, testosterone, estrogen, progesterone), stages/duration of the menstrual cycle, exact site of fertilisation (ampullary-isthmic junction), implantation timing, structure & functions of the placenta (including hCG), and the hormonal trigger for parturition and lactation (oxytocin, prolactin, colostrum).
Spermatogenesis is regulated by GnRH (hypothalamus) → LH & FSH (pituitary). LH acts on Leydig cells to secrete testosterone; FSH acts on Sertoli cells, which support developing sperm and secrete inhibin (a negative feedback signal to FSH).
Oogenesis begins in foetal life — primary oocytes are formed before birth and remain arrested in prophase of meiosis I until puberty. At ovulation, the secondary oocyte is released, arrested again at metaphase of meiosis II, and completes meiosis only if fertilised.
The menstrual cycle (~28 days) has three phases: menstrual phase (~day 1–5), follicular/proliferative phase (rising estrogen, endometrium regrows, ends in ovulation ~day 14), and luteal/secretory phase (corpus luteum secretes progesterone, which maintains the endometrium for potential implantation).
Ovulation is triggered by a sharp LH surge (the "LH surge") around day 14 — a very frequently tested single fact.
Fertilisation normally occurs in the ampullary-isthmic junction of the fallopian tube (oviduct), not in the uterus itself. The resulting zygote undergoes cleavage while moving toward the uterus, reaching the blastocyst stage by the time it implants.
Implantation (attachment of the blastocyst's trophoblast to the endometrium) occurs about 7 days after fertilisation.
The placenta is a chorio-allantoic connection facilitating nutrient/gas/waste exchange between mother and foetus; it also functions as an endocrine gland, secreting hCG, hPL, estrogens and progesterone. hCG (rising rapidly in early pregnancy) is the basis of standard pregnancy tests.
Parturition (childbirth) is initiated by signals from the fully-developed foetus and placenta that trigger mild uterine contractions ("foetal ejection reflex"), which induce a positive-feedback release of oxytocin from the maternal pituitary, progressively strengthening contractions.
Colostrum, the first milk produced during initial days of lactation, is rich in antibodies (particularly IgA) and is critical for building the newborn's early immune protection.
Original questions modelled on recurring NEET question types — not verbatim reproductions of any official paper.
Scaled from direct NCERT recall (Q1–Q6) to mixed NEET-level difficulty (Q7–Q15).
Purely a recall device — not a reinterpretation of the source stories.
The menstrual cycle's length (~28 days) closely tracks Chandra's (the Moon's) own monthly cycle across the sky — a coincidence long noted in Indian tradition and a genuinely useful memory peg. Picture the cycle as the Moon's own phases: the "new moon" opening days are the menstrual phase (days 1–5, shedding what came before); the waxing days that follow are the follicular phase, estrogen steadily rising the way the Moon steadily brightens, cresting at the "full moon" moment of ovulation around day 14; and the waning days after are the luteal phase, progesterone dominant, the corpus luteum fading like the Moon itself if no "new life" arrives to sustain it.
"F for Follicle, L for Leydig/Luteinising the ovulation moment" — FSH grows the follicle (and drives Sertoli cells in males); LH triggers ovulation (and drives Leydig cells/testosterone in males). Say both halves together and the male/female parallel stops being two separate facts to memorise.