Exercise 11.10
If a couple uses oral contraceptive pills but not condoms, which risks remain and why?
Not cross-checked
NCERT prints no numerical answer for this exercise, so this working has not been cross-checked against the book.
The risk of Sexually Transmitted Infections stays exactly as it was — oral pills give no protection against them at all.
An oral contraceptive works by altering hormones so that the release of the egg is changed; it acts inside the woman's body and puts no barrier between the two partners.
STIs spread through the close physical contact itself, so gonorrhoea, herpes, syphilis, genital warts and HIV can still pass from an infected person to an uninfected one.
Only a condom does both jobs — it blocks that transfer and also helps prevent pregnancy.
A second, smaller point: the chapter notes that pills may have some side effects, so relying on them alone carries that cost too.