Exam-ready answers to all 12 exercises of Chapter 3, Reproductive Health (NCERT Class 12 Biology, 2026-27): importance of reproductive health, sex education, improvements in India, population explosion, contraceptives and why gonads are not removed, the ban on amniocentesis for sex determination, assisted reproductive technologies, prevention of STDs, and true/false and correct-the-statement items. All 12 questions are answered, with the key answer highlighted.
Yes. Sex education in schools gives young people correct information about reproductive organs, adolescence, safe and hygienic sexual practices and STIs. It protects them from myths and misconceptions, helps them avoid early pregnancy and infections, and prepares them to lead a healthy, responsible reproductive life.
Yes; it gives correct information, removes myths, and helps prevent STIs and early pregnancies.
Is the use of contraceptives justified? Give reasons.
Solution
Yes. Contraceptives help control the population explosion and let couples plan the size and spacing of their family. They prevent unwanted pregnancies (and so unsafe abortions), and barrier methods like condoms also protect against STIs, including HIV. An ideal contraceptive is safe and reversible and does not interfere with sexual desire.
Yes; they help control population, prevent unwanted pregnancies and (barrier methods) STIs.
Removal of gonads cannot be considered as a contraceptive option. Why?
Solution
Contraceptives should be safe and, ideally, reversible. The gonads (testes and ovaries) also produce hormones needed for secondary sexual characters and normal body functions. Removing them would cause serious hormonal imbalance and permanent sterility, so it is not a contraceptive option. (Sterilisation methods like vasectomy and tubectomy only block the ducts.)
The gonads produce essential hormones, and removing them is irreversible and harmful.
Amniocentesis for sex determination is banned in our country. Is this ban necessary? Comment.
Solution
Yes, the ban is necessary. Amniocentesis is a test of the amniotic fluid meant to detect genetic disorders in the foetus. It was being misused to find the sex of the foetus, followed by abortion of female foetuses (female foeticide). This lowered the female-to-male sex ratio. The legal ban helps stop sex-selective abortions and protects the girl child.
Yes; it was misused for sex determination and female foeticide.
Suggest some methods to assist infertile couples to have children.
Solution
Assisted reproductive technologies (ART):
IVF–ET (in vitro fertilisation and embryo transfer, "test tube baby"): ZIFT (zygote transferred into the fallopian tube) or IUT (embryo with more than 8 blastomeres transferred into the uterus).
GIFT (gamete intrafallopian transfer): an ovum from a donor is transferred into the fallopian tube of a female who cannot produce ova.
ICSI (intracytoplasmic sperm injection): a sperm is injected directly into the ovum.
Artificial insemination (AI/IUI): semen from the husband or a donor is introduced into the vagina or uterus.
(Adoption is another option.)
IVF–ET (ZIFT, IUT), GIFT, ICSI and artificial insemination (IUI).
State True/False with explanation. (a) Abortions could happen spontaneously too. (b) Infertility is defined as the inability to produce a viable offspring and is always due to abnormalities/defects in the female partner. (c) Complete lactation could help as a natural method of contraception. (d) Creating awareness about sex related aspects is an effective method to improve reproductive health of the people.
Solution
(a) True. Pregnancy can end naturally (miscarriage) because of genetic or other problems.
(b) False. Infertility can be due to defects in either partner, or both (male, female or unknown causes).
(c) True. Lactational amenorrhoea: ovulation usually does not occur while the mother breastfeeds fully, up to about six months after childbirth.
(d) True. Awareness helps people avoid STIs and unwanted pregnancies and take better care of reproductive health.
(a) True; (b) False (either partner can be the cause); (c) True (up to about 6 months); (d) True.
Correct the following statements: (a) Surgical methods of contraception prevent gamete formation. (b) All sexually transmitted diseases are completely curable. (c) Oral pills are very popular contraceptives among the rural women. (d) In E. T. techniques, embryos are always transferred into the uterus.
Solution
(a) Surgical methods of contraception prevent gamete transport (they block the vas deferens or fallopian tube), not gamete formation.
(b) Not all STDs are curable: hepatitis B, genital herpes and HIV infection are not completely curable; others are curable if detected early and treated fully.
(c) Oral pills are popular mainly among urban women (less so among rural women).
(d) In ET techniques, embryos are transferred into the fallopian tube (ZIFT, up to 8 blastomeres) or into the uterus (IUT, more than 8 blastomeres).
(a) They prevent gamete transport; (b) HIV, hepatitis B and herpes are not fully curable; (c) popular among urban women; (d) into the fallopian tube or the uterus depending on the stage.
Done with the answers?Now revise the whole chapter: Class 12 Biology notes
For NCERT Biology Class 12 (2026-27 edition) - all 13 chapters, CBSE board 2027
Typed concept notes with labelled diagrams for every topic