- A Copper ions diffuse into vaginal fluid, lowering pH sharply enough to denature sperm membranes
- B Copper ions interfere with sperm enzymes (acrosin, adenyl cyclase), impairing motility and capacitation
- C Copper ions precipitate at the cervical os, forming a physical plug against sperm entry
- D Copper ions provoke a local immune response that generates antibodies against sperm surface antigens
Correct answer: B. Copper ions interfere with sperm enzymes (acrosin, adenyl cyclase), impairing motility and capacitation
Explanation: Copper ions (Cu2+) interfere with key sperm enzymes including acrosin and adenyl cyclase, impair calcium channel function needed for motility, reduce ATP production, and inhibit capacitation, rendering sperm unable to fertilise.
Concept context
Understand reproductive health, family planning, contraception methods, STIs, population control, and assisted reproductive technologies.