NEET 2021 Zoology Question 154 Solution

Contraceptive modalities prevent unwanted conception through distinct physiological and anatomical interventions: - (a) Vaults: Barrier contraceptives made of rubber inserted into the female reproductive tract to cover the cervix before coitus; they mechanically block sperm entry through the cervix. - (b) Intrauterine Devices (IUDs): Foreign bodies (non-medicated, copper-releasing, or hormone-releasing) that trigger a localized sterile inflammatory response, significantly increasing the phagocytosis of sperms within the uterine cavity. - (c) Vasectomy: Male sterilization surgical procedure wherein a small piece of each vas deferens is resected or ligated through a small incision on the scrotum to block sperm transport. - (d) Tubectomy: Female sterilization surgical procedure wherein a small part of each fallopian tube (oviduct) is removed or tied up through an incision in the abdomen or vagina to prevent ovum transport.

Mapping the pairs: - (a) $\rightarrow$ (i) - (b) $\rightarrow$ (iii) - (c) $\rightarrow$ (ii) - (d) $\rightarrow$ (iv) This uniquely aligns with Option (2).