CBSE Class 10 Science 2019 · Paper 31/4/1 · Question 20(b)

Contraception is the deliberate prevention of pregnancy (conception), using devices, chemicals or surgery, so that sexual intercourse does not lead to an unwanted pregnancy. Four methods: (i) mechanical barrier: condom; (ii) chemical: oral pills, which change the hormonal balance so that eggs are not released, or vaginal pills, which contain spermicides that kill sperms; (iii) intra-uterine contraceptive device (IUCD): loop or copper-T placed in the uterus; (iv) surgical: vasectomy (vas deferens blocked in the male) or tubectomy (fallopian tube blocked in the female). Four reasons: (i) to keep a gap between children; (ii) to protect the mother's health; (iii) to keep the family small and give it a better standard of living; (iv) to keep the population under control. (Barrier methods also prevent sexually transmitted diseases; any other relevant reason earns credit.)