Match List-I with List-II. List-I (A) Cytokine barriers (B) Cellular barriers (C) Physiological barriers (D) Physical barriers List-II (I) Mucus coating of respiratory tract (II) Interferons (III) Neutrophils and Macrophages (IV) Tears and Saliva Choose the correct answer from the options given below :
Answer: (C) -(II), (B)-(III), (C)-(IV), (D)-(I). Answer: (C) (A)-(II), (B)-(III), (C)-(IV), (D)-(I) Solution: The four innate barriers are: Cytokine barriers — interferons secreted by virus-infected cells (A-II); Cellular barriers — neutrophils and macrophages that phagocytose microbes (B-III); Physiological barriers — acid, saliva, tears (so tears and saliva, C-IV); Physical barriers — skin and mucus coating of the respiratory/GI/urogenital tracts (D-I).
- A.-(III), (B)-(I), (C)-(II), (D)-(IV)
- B.-(II), (B)-(III), (C)-(I), (D)-(IV)
- C.-(II), (B)-(III), (C)-(IV), (D)-(I)✓
- D.-(III), (B)-(I), (C)-(IV), (D)-(II)
Correct Answer
(C) -(II), (B)-(III), (C)-(IV), (D)-(I)
Solution & Explanation
Answer: (C) (A)-(II), (B)-(III), (C)-(IV), (D)-(I) Solution: The four innate barriers are: Cytokine barriers — interferons secreted by virus-infected cells (A-II); Cellular barriers — neutrophils and macrophages that phagocytose microbes (B-III); Physiological barriers — acid, saliva, tears (so tears and saliva, C-IV); Physical barriers — skin and mucus coating of the respiratory/GI/urogenital tracts (D-I). Why others are wrong: Options that assign interferons to physical/physiological or mucus to a cytokine barrier misclassify the four-barrier scheme of innate immunity. NCERT Reference: NCERT Ch7, p.134-135, lines (p134) 36-56, (p135) 6-8: "Innate immunity consist of four types of barriers"