Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Implants of progestogens alone or in combination with estrogen, placed under the skin of females, have much longer effective periods than contraceptive pills.
Reason (R): The mode of action of progestogen implants placed under the skin is similar to that of contraceptive pills.
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Both (A) and (R) are true but (R) is not the correct explanation of (A).
Oral pills and implants are hormonal contraceptives. Both contain progestogens alone or progestogen–estrogen combinations. Pills are taken daily for 21 days in each cycle, while implants are placed under the skin.
Assertion (A): Implants of progestogens alone or in combination with estrogen, placed under the skin of females, have much longer effective periods than contraceptive pills. — True. The book says the effective periods of implants are much longer than those of pills.
Reason (R): The mode of action of progestogen implants placed under the skin is similar to that of contraceptive pills. — True. Like pills, implants inhibit ovulation and implantation and alter the cervical mucus to prevent or slow the entry of sperms.
Why R does not explain A? A is about how long the method works. R is about how the method prevents pregnancy. Having the same mode of action as pills tells us why implants work, not why they last longer. If anything, a similar action would make the two alike, so R cannot be the cause of the difference in A. So both statements are correct, but R is not the explanation of A.
NCERT Extract:
Population Stabilisation and Birth Control – “… Pills have to be taken daily for a period of 21 days starting preferably within the first five days of menstrual cycle. After a gap of 7 days (during which menstruation occurs) it has to be repeated in the same pattern till the female desires to prevent conception. They inhibit ovulation and implantation as well as alter the quality of cervical mucus to prevent/retard entry of sperms. … Progestogens alone or in combination with estrogen can also be used by females as injections or implants under the skin (Figure 3.3). Their mode of action is similar to that of pills and their effective periods are much longer.”