Chapter 4 — Reproductive Health — covers population control, contraception, STDs, infertility, and assisted reproductive technologies. This chapter carries 5-7 marks and is largely factual with important social relevance.
Key Concepts
Contraceptive Methods
| Category | Method | Examples/Details |
|---|---|---|
| Natural/Traditional | Periodic abstinence | Avoid intercourse during days 10-17 of cycle (fertile window) |
| Coitus interruptus | Withdrawal before ejaculation | |
| Lactational amenorrhea | Breastfeeding prevents ovulation (up to 6 months) | |
| Barrier | Condoms (M/F) | Also prevent STDs; most popular method |
| Diaphragm, cervical cap | Cover cervix; used with spermicides | |
| IUDs | Non-medicated | Lippes loop — increases phagocytosis of sperms |
| Copper-releasing | CuT, Cu7, Multiload 375 — Cu ions reduce sperm motility | |
| Hormone-releasing | Progestasert, LNG-20 — make uterus unsuitable for implantation | |
| Hormonal | Oral pills | Saheli (centchroman) — non-steroidal, once-a-week pill developed in India |
| Injections/implants | Progestogens — prevent ovulation | |
| Surgical (Sterilisation) | Vasectomy (male) | Vas deferens cut and tied — blocks sperm transport |
| Tubectomy (female) | Fallopian tubes cut and tied — blocks egg transport |
Saheli — developed at CDRI Lucknow; non-steroidal, once-a-week, very few side effects. A favourite exam fact!
Sexually Transmitted Diseases (STDs/STIs)
| Disease | Causative Organism | Type | Symptoms |
|---|---|---|---|
| Gonorrhoea | Neisseria gonorrhoeae | Bacteria | Urethral discharge, pain during urination |
| Syphilis | Treponema pallidum | Bacteria | Painless ulcer (chancre), rash, can affect brain |
| Chlamydiasis | Chlamydia trachomatis | Bacteria | Urethritis, may cause infertility |
| Genital herpes | Herpes simplex virus | Virus | Painful blisters on genitals |
| Genital warts | Human papillomavirus (HPV) | Virus | Warts on genitals; linked to cervical cancer |
| HIV/AIDS | Human immunodeficiency virus | Virus | Destroys helper T-cells → immunodeficiency |
| Hepatitis B | Hepatitis B virus | Virus | Liver damage |
| Trichomoniasis | Trichomonas vaginalis | Protozoan | Vaginal discharge, itching |
Infertility & Assisted Reproductive Technologies (ART)
| Technique | Description |
|---|---|
| IVF (Test tube baby) | Fertilisation outside body → embryo transferred to uterus (ET) |
| ZIFT | Zygote transferred to fallopian tube (at zygote stage) |
| GIFT | Gamete (ovum from donor + sperm) transferred to fallopian tube |
| ICSI | Single sperm injected directly into ovum (for low sperm count) |
| AI (Artificial Insemination) | Semen collected and introduced into uterus (IUI) |
| Surrogacy | Embryo implanted in another woman’s uterus |
Population Control — India
- India was the first country to adopt family planning (1951)
- RCH (Reproductive and Child Health) programme by government
- Statutory raising of marriageable age: Males 21, Females 18
- Incentives for small family norm; free contraceptives
Medical Termination of Pregnancy (MTP)
- Legal in India (MTP Act, 1971) up to 20 weeks (extended to 24 weeks in 2021 for special categories)
- Permitted for: failure of contraception, rape, risk to mother’s health, foetal abnormalities
- Misuse: illegal sex-selective abortions → Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act to prevent sex determination
Important Definitions
| Term | Definition |
|---|---|
| Reproductive Health | Total well-being in all aspects of reproduction — physical, emotional, social |
| IVF | In Vitro Fertilisation — fertilisation outside body in lab conditions |
| Amniocentesis | Foetal test for genetic disorders (banned for sex determination in India) |
| Infertility | Inability to conceive after one year of unprotected intercourse |
Solved Examples — NCERT Based
Example 1
Q: Why are condoms considered the best contraceptive?
Solution: Condoms are preferred because they: (1) prevent pregnancy (barrier method), (2) protect against STDs including HIV/AIDS, (3) are easily available, (4) have no side effects, (5) do not require medical supervision.
Example 2
Q: Differentiate between ZIFT and GIFT.
Solution: ZIFT (Zygote Intra-Fallopian Transfer): fertilisation is done in the lab (IVF) → zygote/early embryo (up to 8 cells) is transferred to the fallopian tube. GIFT (Gamete Intra-Fallopian Transfer): unfertilised ovum from a donor female and sperm are directly transferred into the fallopian tube → fertilisation occurs inside the body.
Important Questions for Board Exams
1 Mark
- What is Saheli?
- Name two STDs caused by bacteria.
- What is amniocentesis?
3 Mark
- Describe the different types of contraceptive methods.
- What are the causes of infertility? Describe any two ART procedures.
5 Mark
- What is reproductive health? Discuss the various contraceptive methods with their advantages and disadvantages.
Quick Revision Points
- Contraceptives: natural (abstinence, LAM), barrier (condom), IUD (CuT), hormonal (Saheli), surgical (vasectomy/tubectomy)
- Only condoms protect against STDs
- STDs: bacterial (gonorrhoea, syphilis) + viral (HIV, herpes, HPV, Hep B)
- ART: IVF-ET, ZIFT, GIFT, ICSI, AI/IUI
- IVF = fertilisation outside; GIFT = gamete transfer (fertilisation inside)
- MTP legal up to 20 weeks; PCPNDT Act bans sex determination
- Saheli: non-steroidal, once/week, CDRI Lucknow
Chapter Navigation
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Next: Principles of Inheritance and Variation Class 12 Notes
Related Chapters in Class 12 Biology
- Human Reproduction Class 12 Notes
- Sexual Reproduction in Flowering Plants Class 12 Notes
- Reproduction in Organisms Class 12 Notes
Practice What You Learned
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