| CONTRACEPTIVE METHOD | MODE OF ACTION |
| A. Tubectomy | Makes the uterus unsuitable for implantation |
| B. Oral Pills | Inhibit ovulation and implantation |
| C. Diaphragm | Increases phagocytosis of sperms within uterus |
| D. IUDs | Barriers made of rubber that are inserted into the female reproductive tract to cover the cervix during coitus. |
Which of the following contraceptive methods correctly matches with its mode of action?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → B
Each contraceptive method works in its own way. Barriers stop sperm from reaching the ovum. IUDs act inside the uterus. Pills are hormones that act on ovulation and implantation. Surgical methods block the path of the gametes. Only one row of the table pairs a method with its own mode of action.
Option (1) A — Incorrect. In tubectomy a small part of the fallopian tube is removed or tied up, so the ovum cannot meet the sperm. Making the uterus unsuitable for implantation is an extra action of the hormone-releasing IUDs.
Option (2) B — Correct. Oral pills contain small doses of progestogens or progestogen–estrogen combinations. They inhibit ovulation and implantation and also make the cervical mucus hard for sperm to pass.
Option (3) C — Incorrect. A diaphragm is a rubber barrier that covers the cervix. Increasing phagocytosis of sperms within the uterus is the action of IUDs, not of a diaphragm.
Option (4) D — Incorrect. Intra Uterine Devices (IUDs) are placed inside the uterus. The rubber barrier that covers the cervix during coitus describes diaphragms, cervical caps and vaults.
NCERT Extract:
Population Stabilisation and Birth Control – “… Diaphragms, cervical caps and vaults are also barriers made of rubber that are inserted into the female reproductive tract to cover the cervix during coitus. … IUDs increase phagocytosis of sperms within the uterus and the Cu ions released suppress sperm motility and the fertilising capacity of sperms. The hormone releasing IUDs, in addition, make the uterus unsuitable for implantation and the cervix hostile to the sperms. … Pills have to be taken daily for a period of 21 days starting preferably within the first five days of menstrual cycle. … They inhibit ovulation and implantation as well as alter the quality of cervical mucus to prevent/retard entry of sperms. … In vasectomy, a small part of the vas deferens is removed or tied up through a small incision on the scrotum (Figure 3.4a) whereas in tubectomy, a small part of the fallopian tube is removed (Figure 3.4b) or tied up through a small incision in the abdomen or through vagina.”