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State Board · Class 12 · Biology

Lesson 2: Reproduction in Lower and Higher Animals

7 concepts · 56 practice questions with answers · Free to read

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Asexual reproduction in animals and overview

Link to Std 9–10

Std 8–11 introduced human reproduction and cell division; here we study gametogenesis, the menstrual cycle, pregnancy and reproductive health in detail.

From daily life

A small bud grows on a Hydra, separates and becomes a new Hydra.

Simple definition

Reproduction = forming new individuals like the parent. Asexual: one parent, no meiosis or gametes (clones). Sexual: formation and fusion of gametes (amphimixis).

OverviewReproduction in animals: overviewGemmuleBuddingRegenerationSpongilla; archaeocytesHydra, coralsPlanaria; repairGemmule: internal bud for hard times (sponges)Budding: bud at base → tentacles → detaches; clonesRegeneration is not reproduction; Planaria also splitsAsexual: no meiosis/gametes; single parentSexual (amphimixis): formation + fusion of gametesTwo phases: juvenile and reproductive maturityEvents: pre-fertilization → fertilization → post-fertilizationSeasonal breeders: goat, sheep; continuous: humans, apesPrimary sex organs: testis, ovary; others = secondarySecondary sexual characters: beard, breasts, voice (dimorphism)Humans: internal fertilization; viviparous

In the figure : Asexual reproduction and overview of sexual reproduction.

Rule 1 : Gemmule, budding and regeneration — Gemmule: only in sponges (Spongilla); an internal mass of archaeocytes wrapped in a thick coat; survives bad times, hatches into a new sponge later. Budding: Hydra, corals, some ascidians; bud at base → tentacles → detaches. Regeneration: regrowing a lost part; not reproduction, but Planaria can also split into two clones.

  • Easy : Gemmule = sponge.
  • Medium : Budding = Hydra.
  • Exam-type (CET) : Regeneration ≠ reproduction.

Rule 2 : Overview of sexual reproduction — Two phases: juvenile (growth; no breeding) and reproductive maturity. Events: pre-fertilization (gametogenesis, gamete transfer), fertilization, post-fertilization (zygote, embryogenesis). Seasonal breeders: goat, sheep; continuous breeders: humans, apes. Humans: gametogenesis → insemination → internal fertilization → zygote → gestation → parturition. Primary sex organs: testis, ovary; others = secondary. Secondary sexual characters (beard, breasts, voice) = sexual dimorphism.

  • Easy : Primary = testis, ovary.
  • Medium : Human = continuous breeder.
  • Exam-type (CET) : Amphimixis = sexual mixing.
Remember

G-B-R: Gemmule (sponge), Budding (Hydra), Regeneration (Planaria).

Common mistake and CET trap

‘Regeneration is reproduction’ is wrong. Trap: ‘gemmules occur in all animals’ is wrong (sponges only).

Shortcut

Memory clue : "Gemmule = a gem in a shell".

Spot the difference

MethodAnimal
GemmuleSpongilla
BuddingHydra, coral
RegenerationPlanaria

Practice questions

Easy
  1. 1What is asexual reproduction?
  2. 2Where do gemmules occur?
  3. 3Gemmule is made of?
Medium
  1. 4Reproduction in Hydra?
  2. 5Example of continuous breeder?
  3. 6Primary sex organs?
Challenging
  1. 7Example of secondary sexual character?
  2. 8What is amphimixis?
Show answers (try them yourself first)
  1. 1From one parent without gametes.
  2. 2In sponges.
  3. 3Archaeocytes.
  4. 4Budding.
  5. 5Humans, apes.
  6. 6Testis and ovary.
  7. 7Beard / breasts.
  8. 8Sexual reproduction.

Male reproductive system

From daily life

A factory makes goods that travel through a pipeline gaining fluids on the way — just like sperm.

Simple definition

Male system: testes (primary), accessory ducts, accessory glands, external genitalia (penis, scrotum).

Male systemMale reproductive systemTestisEpididymisVas deferensDuct pathSeminiferous tubules→ Rete testis→ Vasa efferentia (12–20)→ Epididymis→ Vas deferens→ Ejaculatory duct→ Urethra → meatusSertoli: nutrition; Leydig: testosterone; testis 4–5 cmScrotum: 2–3 °C cooler; cryptorchidism = undescended testisSeminal vesicle ~60%: fructose, fibrinogen, prostaglandinsProstate ~30%: citric acid, acid phosphataseCowper's: mucous lubricantSemen 2.5–4 ml; ~400 million sperm; pH 7.2–7.7Penis: 2 corpora cavernosa + 1 corpus spongiosum; glans

In the figure : Male reproductive system and duct path.

Rule 1 : Testes, scrotum and histology — Testes: mesodermal; descend into the scrotum via the inguinal canal; 4–5 cm; 200–300 lobules, each with 1–4 seminiferous tubules (germinal epithelium = spermatogonia + Sertoli cells: nutrition). Between tubules: Leydig (interstitial) cells: testosterone. Coverings: tunica albuginea, tunica vaginalis. The scrotum keeps 2–3 °C cooler (cremaster + dartos). Failure to descend = cryptorchidism (sterility); gubernaculum; inguinal hernia.

  • Easy : Sertoli = nutrition; Leydig = testosterone.
  • Medium : Scrotum = cooler.
  • Exam-type (CET) : Testis must stay cool.

Rule 2 : Ducts, glands and semen — Ducts: seminiferous tubules → rete testis → vasa efferentia (12–20) → epididymis (sperm mature) → vas deferens → ejaculatory duct (joined by seminal vesicle) → urethra (urine + semen; urinogenital duct). Glands: seminal vesicles (~60%; alkaline; fructose, fibrinogen, prostaglandins), prostate (~30%; slightly acidic; citric acid, acid phosphatase), Cowper's (lubricant). Semen: 2.5–4 ml, ~400 million sperm, pH 7.2–7.7. Penis: 2 corpora cavernosa + 1 corpus spongiosum; glans; prepuce.

  • Easy : Fructose = sperm energy.
  • Medium : Seminal vesicle ≈ 60% of semen.
  • Exam-type (CET) : Urethra = common passage.
Remember

S-R-V-E-V-E-U: Seminiferous, Rete, Vasa efferentia, Epididymis, Vas deferens, Ejaculatory duct, Urethra.

Common mistake and CET trap

‘Sertoli cells make testosterone’ is wrong (Leydig). Trap: ‘prostate ~60%’ is wrong (30%).

Shortcut

Memory clue : "Leydig = lead hormone; Sertoli = sustains sperm".

Spot the difference

Gland% of semenKey
Seminal vesicle~60%Fructose
Prostate~30%Citric acid
Cowper'ssmallLubricant

Practice questions

Easy
  1. 1Role of seminiferous tubule?
  2. 2What do Leydig cells make?
  3. 3Role of Sertoli cells?
Medium
  1. 4Why is the scrotum cooler?
  2. 5Role of epididymis?
  3. 6What is cryptorchidism?
Challenging
  1. 7Volume of semen?
  2. 8Role of Cowper's gland?
Show answers (try them yourself first)
  1. 1Sperm production.
  2. 2Testosterone.
  3. 3Nourish developing sperm.
  4. 4For spermatogenesis.
  5. 5Sperm maturation.
  6. 6Undescended testis.
  7. 72.5–4 ml.
  8. 8Lubrication.

Female reproductive system

From daily life

The ovary is the egg store, the oviduct the passage, the uterus the baby's home.

Simple definition

Female system: ovaries (primary), oviducts, uterus, vagina, external genitalia, vestibular and mammary glands.

Female systemFemale reproductive systemOvaryOvaryOviductUterusVaginaOviduct: 3 partsInfundibulum (fimbriae)Ampulla = site of fertilizationIsthmusUterus: 3 partsFundus (implantation)BodyCervix (2.5 cm)Ovary 3×1.5×1 cm: medulla + cortex (follicles); 5 hormones~1 million follicles at birth; 60–80 thousand at pubertyGraafian follicle: theca externa/interna, granulosa, antrumZona pellucida, corona radiata, liquor folliculiAfter ovulation: corpus luteum → corpus albicansMenarche ~13 y; menopause 45–55; ~416 eggsMammary glands: lactiferous ducts; vestibular glands

In the figure : Female reproductive system.

Rule 1 : Ovary and follicles — Ovary: 3 × 1.5 × 1 cm; central medulla + outer cortex (germinal epithelium; follicles). 5 hormones: estrogen, progesterone, relaxin, activin, inhibin. ~2 million primordial follicles in the foetus; ~1 million at birth; 60–80 thousand at puberty (atresia). Follicle: primordial → primary → secondary → tertiary → Graafian. Graafian: theca externa/interna, membrana granulosa, antrum (liquor folliculi), zona pellucida, corona radiata, cumulus oophorus. After ovulation corpus luteum → (no fertilization) corpus albicans. Menarche ~13 y; menopause 45–55; ~416 eggs.

  • Easy : Theca interna = estrogen.
  • Medium : Atresia = follicle loss.
  • Exam-type (CET) : 32 years × 13 = 416.

Rule 2 : Oviduct, uterus, vagina, breast — Oviduct: infundibulum (fimbriae, ostium), ampulla (fertilization here), isthmus. Uterus: pear-shaped, 7.5 × 5 × 2.5 cm; fundus (implantation), body, cervix (~2.5 cm). Wall: perimetrium, myometrium, endometrium. Vagina: birth canal. External: mons pubis, labia, clitoris, hymen; vestibular (Bartholin's) glands. Mammary glands: lobes → alveoli → lactiferous ducts → nipple.

  • Easy : Ampulla = fertilization.
  • Medium : Fundus = implantation.
  • Exam-type (CET) : Endometrium = inner lining.
Remember

Oviduct: I-A-I (Infundibulum, Ampulla, Isthmus); uterus: F-B-C.

Common mistake and CET trap

‘Fertilization in the uterus’ is wrong (ampulla). Trap: ‘corpus albicans secretes hormones’ is wrong (corpus luteum).

Shortcut

Memory clue : "Ampulla = action place; fundus = fix the embryo".

Spot the difference

PartRole
InfundibulumCatches the egg
AmpullaFertilization
FundusImplantation
CervixNeck of uterus

Practice questions

Easy
  1. 1Two roles of ovary?
  2. 2What is atresia?
  3. 3Layers of Graafian follicle?
Medium
  1. 4Site of fertilization?
  2. 5Site of implantation?
  3. 6Corpus luteum gives?
Challenging
  1. 7When is menarche?
  2. 8When is menopause?
Show answers (try them yourself first)
  1. 1Eggs + hormones.
  2. 2Degeneration of follicles.
  3. 3Theca, granulosa, zona pellucida…
  4. 4Ampulla.
  5. 5Fundus.
  6. 6Progesterone.
  7. 7~13 years.
  8. 845–55 years.

Menstrual cycle and gametogenesis

From daily life

A monthly rhythm: prepare, release an egg mid-way, then shed the lining.

Simple definition

The menstrual cycle lasts ~28 days: menses → proliferative → ovulation → secretory. Gametogenesis = formation of sperm (spermatogenesis) and egg (oogenesis).

Cycle and gametogenesisMenstrual cycle and gametogenesisMensesProliferativeSecretory (luteal)151428Ovulation (LH surge)Hormones: FSH → follicle; estrogen → endometrium; LH → ovulationCorpus luteum → progesterone; degenerates in 2 weeks if no fertilizationIf fertilized, hCG sustains corpus luteum (pregnancy marker)SpermatogenesisPGC 2n → spermatogonia → primary spermatocyte 2n→ 2 secondary spermatocytes n → 4 spermatids → 4 spermsSpermiogenesis: acrosome, spiral mitochondriaOogenesisOogonia → primary oocyte 2n (meiosis I arrest)→ secondary oocyte n + polar body 1 (met. II)After sperm entry: meiosis II → ovum + polar body 2Sperm: head (acrosome), middle piece (mitochondria), tailFSH drives spermatogenesis; GnRH starts at pubertyOvum: zona pellucida, corona radiata, vitelline membrane1 oocyte → 1 ovum + polar bodies; 1 spermatocyte → 4 spermsHygiene: change pads every 4–5 hours

In the figure : 28-day cycle, spermatogenesis and oogenesis.

Live figure

Menstrual cycle and gametogenesis

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Open in the app

Rule 1 : Menstrual cycle — Menses (days 1–5): endometrium is shed. Proliferative / follicular (5–13): FSH → follicles, estrogen → endometrium regrows. Ovulation (day 14): LH surge (positive feedback) → Graafian follicle ruptures releasing the secondary oocyte. Secretory / luteal (15–28; longest): corpus luteum → progesterone + estrogen + inhibin; endometrium 8–10 mm. If fertilized, hCG sustains the corpus luteum; if not, corpus albicans in 2 weeks and a new cycle.

  • Easy : 5 + 9 + 14 = 28.
  • Medium : LH surge = ovulation.
  • Exam-type (CET) : Secretory = progesterone.

Rule 2 : Spermatogenesis and oogenesis — Spermatogenesis: multiplication (PGC → spermatogonia 2n, mitosis) → growth (primary spermatocyte 2n) → maturation (meiosis I → 2 secondary spermatocytes n → meiosis II → 4 spermatids) → spermiogenesis (acrosome, mitochondria in middle piece, tail). GnRH → FSH. Sperm: head (acrosome: hyaluronidase), neck (2 centrioles), middle piece (mitochondria), tail. Oogenesis: before birth oogonia → primary oocyte 2n, arrested in meiosis I; at puberty meiosis I completes → secondary oocyte + 1st polar body; the secondary oocyte arrests at metaphase II and is ovulated; meiosis II completes only on sperm entry → ovum + 2nd polar body. 1 oocyte → 1 ovum; 1 spermatocyte → 4 sperms.

  • Easy : Oocyte: meiosis I starts before birth, arrests.
  • Medium : Ovulated cell = secondary oocyte.
  • Exam-type (CET) : 1 → 1 (female); 1 → 4 (male).
Remember

5-9-14 = 28: menses 5, proliferative 9, secretory 14. One egg, polar bodies discarded.

Common mistake and CET trap

‘Primary oocyte is ovulated’ is wrong (secondary). Trap: ‘oogenesis starts at puberty’ is wrong (before birth).

Shortcut

Memory clue : "LH = Launch Hormone (launches the egg)".

Spot the difference

PointSpermEgg
Startspubertybefore birth
Products1 → 41 → 1 + polar bodies
HormoneFSHFSH, LH

Practice questions

Easy
  1. 1Length of the cycle?
  2. 2When is ovulation?
  3. 3What triggers ovulation?
Medium
  1. 4Longest phase?
  2. 5Role of hCG?
  3. 6Sperms from one primary spermatocyte?
Challenging
  1. 7Role of acrosome?
  2. 8Cell that is ovulated?
Show answers (try them yourself first)
  1. 1~28.
  2. 2Day 14.
  3. 3LH surge.
  4. 4Secretory / luteal.
  5. 5Sustains corpus luteum.
  6. 64.
  7. 7Digests zona pellucida.
  8. 8Secondary oocyte (metaphase II).

Fertilization and early embryonic development

From daily life

Millions of sperm race, but only one enters the egg and the door then shuts.

Simple definition

Fertilization = haploid sperm + egg → diploid zygote (in the ampulla). Then cleavage → morula → blastocyst → implantation → gastrulation.

Fertilization and developmentFertilization and early developmentZygoteCleavageMorulaBlastocystGastrulaCapacitation (5–6 h) → acrosome reaction → zona lysinFertilizin–antifertilizin = species-specific recognitionCortical reaction → fertilization membrane → no polyspermySyngamy/karyogamy: 2n zygote; centrioles from spermFertilization in ampulla; ovum ~24 h, sperm 24–48 h viableOf 200–400 million sperm only a few hundred reach the ampullaCleavage: mitosis; no growth; blastomeresBlastocyst: trophoblast (outer) + inner cell mass (embryoblast)Implantation: day ~7; fundus; complete by day 10Syncytiotrophoblast + cytotrophoblastGastrulation: ectoderm, mesoderm, endodermEctoderm: skin, nervous system; mesoderm: muscle, blood, heartEndoderm: gut lining, liver, lungs

In the figure : Steps of fertilization and early development.

Rule 1 : Mechanism of fertilization — ~50% of sperm are destroyed in the vagina; the rest undergo capacitation (5–6 h) and become hyperactive; prostaglandins and oxytocin help; speed 1.5–3 mm/min. Sperm live 24–48 h, the egg ~24 h. Acrosome reaction: hyaluronidase, zona lysin → penetrate corona radiata and zona pellucida; fertilizin–antifertilizin (species-specific). Cortical reaction: fertilization membrane → blocks polyspermy. The egg completes meiosis II → 2nd polar body; pronuclei fuse = syngamy (karyogamy) → zygote 2n; centrioles come from the sperm. Significance: diploid restored, sex fixed, variation.

  • Easy : Capacitation = 5–6 h.
  • Medium : Cortical reaction blocks polyspermy.
  • Exam-type (CET) : Centrioles come from the sperm.

Rule 2 : Cleavage, implantation, gastrulation — Cleavage = repeated mitosis of the zygote (without growth) → blastomeres → morula → blastocyst (outer trophoblast + inner cell mass/embryoblast). The zona pellucida hides the sticky trophoblast until the uterus. Implantation ~day 7, in the fundus; syncytio- + cytotrophoblast; complete by day 10. Gastrulation: hypoblast (endoderm, yolk sac), epiblast (ectoderm, amnion); ~day 15 primitive streak → mesoderm → 3 layers. Ectoderm: skin, nervous system; mesoderm: muscle, blood, heart, kidney; endoderm: gut lining, liver, lungs.

  • Easy : Cleavage = division without growth.
  • Medium : Trophoblast outer; ICM inner.
  • Exam-type (CET) : 3 layers: ecto-, meso-, endoderm.
Remember

Z-C-M-B-I-G: Zygote, Cleavage, Morula, Blastocyst, Implantation, Gastrula.

Common mistake and CET trap

‘Cells grow during cleavage’ is wrong. Trap: ‘implantation in the ampulla’ is wrong (fundus).

Shortcut

Memory clue : "Trophoblast = sticks to the uterus; ICM = Inner Child Mass".

Spot the difference

LayerForms
EctodermSkin, brain
MesodermMuscle, blood
EndodermLiver, lungs

Practice questions

Easy
  1. 1What is capacitation?
  2. 2What does the acrosome release?
  3. 3How is polyspermy avoided?
Medium
  1. 4What is syngamy?
  2. 5What is a morula?
  3. 6Two parts of blastocyst?
Challenging
  1. 7When does implantation begin?
  2. 8Mesoderm forms via?
Show answers (try them yourself first)
  1. 1Sperm becoming hyperactive.
  2. 2Hyaluronidase, zona lysin.
  3. 3Fertilization membrane.
  4. 4Fusion of pronuclei.
  5. 5Solid ball of cells.
  6. 6Trophoblast + inner cell mass.
  7. 7Day ~7.
  8. 8Primitive streak.

Pregnancy, placenta, parturition and lactation

From daily life

For nine months mother and baby are linked by the placenta, a living bridge.

Simple definition

Gestation ~266 days (from fertilization) = 280 days (from LMP), 3 trimesters. Placenta = mother–foetus link. Parturition = birth; lactation = milk production.

Pregnancy and parturitionPregnancy, placenta, parturitionTrimester 1Trimester 2Trimester 30–12 wk: organogenesis; heartbeat 13–26: rapid growth; hCG falls; ~327–birth: ~3–4 kg, 50 cm~266 days from fertilization (280 from LMP)Placenta: chorionic villi (foetal) + maternal part; exchange of gases/food/wastesUmbilical cord: 2 arteries (to placenta) + 1 veinHormones: hCG, HPL, estrogen, progesterone, relaxinOnly organ made of tissues of two individualsParturition: foetal ACTH/corticoids → maternal oxytocin → contractions1 Dilation → 2 Expulsion (20–60 min) → 3 After-birth (10–45 min)Lactation: prolactin; colostrum = first milk with IgAAmnion protects the embryo; yolk sac; chorionSonography at 18–20 wk; amniocentesis for sex determination is bannedCord blood banking: stores stem cells

In the figure : Trimesters, placenta and parturition.

Rule 1 : Trimesters and placenta — 1st (0–12 weeks): organogenesis; at 8 weeks a foetus (~3 cm); heartbeat by 6 weeks; morning sickness; high progesterone, periods stop. 2nd (13–26): rapid growth (~30 cm); hCG falls, corpus luteum regresses, the placenta makes progesterone. 3rd (27–birth): ~3–4 kg, 50 cm. Placenta: disc-shaped; foetal part = chorionic villi, plus a maternal part; supplies O₂, food, antibodies; removes CO₂, wastes; hormones hCG, HPL, estrogen, progesterone, relaxin. The only organ made of tissues from two individuals. Umbilical cord: 2 arteries (to placenta) + 1 vein. Amnion + amniotic fluid protect.

  • Easy : 266 days from fertilization.
  • Medium : Placenta = mother + foetus.
  • Exam-type (CET) : Cord: 2 arteries + 1 vein.

Rule 2 : Parturition and lactation — Control: the mature foetus releases ACTH + corticoids → estrogen:progesterone ratio rises, oxytocin receptors increase → the mother's pituitary releases oxytocin → strong myometrial contractions (positive feedback). Three stages: dilation (cervix opens; amnion ruptures), expulsion (20–60 min; cord tied and cut), after-birth (placenta, 10–45 min). Lactation: prolactin makes milk; the first milk colostrum (yellow; proteins, lactose, IgA; low fat) gives the baby resistance.

  • Easy : Oxytocin = labour contractions.
  • Medium : Prolactin = milk.
  • Exam-type (CET) : Colostrum = antibodies.
Remember

Oxytocin = Out (baby out); prolactin = production (milk).

Common mistake and CET trap

‘Prolactin causes birth’ is wrong (oxytocin). Trap: ‘cord has 2 veins’ is wrong (2 arteries).

Shortcut

Memory clue : "2 arteries + 1 vein; colostrum = care-first milk".

Spot the difference

HormoneSourceRole
hCGPlacentaSustains corpus luteum
OxytocinPituitaryLabour contractions
ProlactinPituitaryMilk production

Practice questions

Easy
  1. 1Gestation period?
  2. 2When is heartbeat heard?
  3. 3Role of placenta?
Medium
  1. 4Vessels in cord?
  2. 5Placental hormones?
  3. 6Three stages of labour?
Challenging
  1. 7What is colostrum?
  2. 8Hormone for lactation?
Show answers (try them yourself first)
  1. 1266 days from fertilization.
  2. 2At 6 weeks.
  3. 3Exchange + hormones.
  4. 42 arteries + 1 vein.
  5. 5hCG, HPL, estrogen, progesterone, relaxin.
  6. 6Dilation, expulsion, after-birth.
  7. 7First milk (with IgA).
  8. 8Prolactin.

Reproductive health, birth control, STDs and infertility

From daily life

Family planning means choosing when to have a baby; it needs information and means.

Simple definition

Reproductive health (WHO) = total physical, emotional, behavioural and social wellbeing in reproduction. Contraceptives prevent fertilization. ART helps in infertility.

Reproductive healthReproductive health, birth control, infertilityTemporaryPermanentARTSafe period, withdrawal, LAMCondom (Nirodh), diaphragmIUD: Lippes, Cu-TPills, Saheli, injectablesVasectomy (male)Tubectomy (female)MTP: abortion, Act of 1971IVF–ET (test tube baby)ZIFT · IUT · GIFTICSI · AI / IUIWHO: reproductive health = physical + emotional + social wellbeingRCH programme: awareness, facilities; lower IMR, MMR, infertilitySTDs: gonorrhoea, syphilis, herpes, chlamydia, hepatitis B, HIVCondom also protects against STDsMarriageable age: boy 21, girl 18ZIFT: zygote into fallopian tube; IUT: into uterusGIFT: gametes into tube; ICSI: sperm injected into ovumInfertility: physical, congenital, infection, stress, drugsSex education removes myths, teaches safe habits

In the figure : Birth control, STDs and ART.

Rule 1 : Reproductive health and birth control — RCH programme: awareness, facilities, support; reducing infertility, infant (IMR) and maternal (MMR) mortality; sex education in schools; ban on amniocentesis for sex determination; marriageable age boy 21, girl 18. Temporary: natural/safe period, coitus interruptus, lactational amenorrhea (high failure); chemical (foam, jelly); barrier — condom (Nirodh) (also protects against STDs), diaphragm; IUDs (Lippes loop, Copper-T, hormonal); pills, Saheli. Permanent: vasectomy, tubectomy. MTP (Act of 1971): legal abortion under medical advice.

  • Easy : Condom also stops STDs.
  • Medium : Vasectomy male; tubectomy female.
  • Exam-type (CET) : IUD sits in the uterus.

Rule 2 : STDs and infertility: ART — STDs: gonorrhoea, syphilis, genital herpes, chlamydiasis, hepatitis B, HIV/AIDS; safe habits, condoms, early treatment. Infertility: physical, congenital, infection, stress, drugs. ART: IVF–ET (fertilization in the lab → ‘test tube baby’), ZIFT (zygote into the fallopian tube), IUT (embryo with more than 8 blastomeres into the uterus), GIFT (gametes into the tube), ICSI (sperm injected into the egg), AI / IUI (semen into the vagina/uterus).

  • Easy : ZIFT = tube; IUT = uterus.
  • Medium : ICSI = directly into egg.
  • Exam-type (CET) : HIV is an STD.
Remember

ZIFT = Zygote Into Fallopian Tube; IUT = Into Uterus; ICSI = Inject Sperm Into egg.

Common mistake and CET trap

‘Safe period is foolproof’ is wrong (high failure). Trap: ‘vasectomy is female’ is wrong.

Shortcut

Memory clue : "Vasectomy = vas deferens (male); tubectomy = tubes (female)".

Spot the difference

MethodType
CondomBarrier + STD protection
Cu-TIUD
Vasectomy / TubectomyPermanent
IVF / ICSIART

Practice questions

Easy
  1. 1What is reproductive health?
  2. 2Aim of RCH?
  3. 3What is Nirodh?
Medium
  1. 4Examples of IUD?
  2. 5What is vasectomy?
  3. 6What is IVF?
Challenging
  1. 7What is ICSI?
  2. 8Example of an STD?
Show answers (try them yourself first)
  1. 1Total wellbeing in reproduction.
  2. 2Reduce IMR, MMR, infertility.
  3. 3Government condom.
  4. 4Lippes loop, Cu-T.
  5. 5Male sterilisation.
  6. 6Fertilization outside the body.
  7. 7Sperm injected into egg.
  8. 8Syphilis / HIV.

Quick revision of the whole lesson

ConceptKey fact
AsexualGemmule, budding, regeneration
MaleSertoli, Leydig; semen 60/30%
FemaleGraafian follicle; ampulla = fertilization
Cycle5-9-14 = 28; ovulation day 14
FertilizationZygote → blastocyst → gastrula
Pregnancy266 days; 3 trimesters
HealthRCH; IUD; ZIFT/IUT

🎯 Most important points for the exam

  • Gemmule, budding.
  • Male system and semen.
  • Ovary, Graafian follicle.
  • Menstrual cycle; gametogenesis.
  • Fertilization and cleavage.
  • Placenta, parturition.
  • Birth control, ART.
Study mantra

Understand the concept → draw the figure → memorise the key points → solve questions yourself.