CBSE Class 10 Science 2019 · Paper 31/1/1/C · Question 18(b)

(a) Gonorrhoea and syphilis. They can be prevented by using a condom (a covering for the penis, or a similar covering worn in the vagina) during sexual intercourse, and by avoiding sexual contact with an infected person or with many partners. (b) (i) Oral pills, which change the hormonal balance so that eggs are not released. (ii) A loop or copper-T placed in the uterus. (iii) Surgical methods: vasectomy, in which the vas deferens of the male is blocked so that sperm are not transferred, or tubectomy, in which the fallopian tube of the female is blocked so that the egg does not reach the uterus. (c) (i) They prevent unwanted pregnancies and help to keep the family small and the population in check. (ii) They allow proper spacing between children, which protects the health of the mother. (iii) Barrier methods also protect against sexually transmitted diseases such as gonorrhoea, syphilis and HIV-AIDS.