चिकित्सा शब्दावली में, प्रतिरक्षा (Immunity) को सबसे अच्छी तरह परिभाषित किया गया है:

Which pair of diseases represents classic examples where herd immunity is achieved through successful mass vaccination programs?

Match the type of graft in Column (A) with its correct description in Column (B): Column (A) (A) Autograft (B) Isograft (C) Allograft (D) Xenograft Column (B) (i) Graft between genetically different individuals of the same species (ii) Graft between individuals of different species (iii) Graft between genetically identical individuals (iv) Transplant from one body part to another on the same individual