Match the LIST-I with LIST-II
| LIST-I | LIST-II |
|---|---|
| Types of immunity barriers | Examples |
| A. Physical barriers | I. Polymorpho-nuclear leukocytes |
| B. Physiological barriers | II. Mucus coating of epithelium lining of the respiratory tract |
| C. Cellular barriers | III. Interferons |
| D. Cytokine barriers | IV. Saliva in mouth |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A-II, B-IV, C-I, D-III
(A) Physical barriers — this matches (II) Mucus coating of epithelium lining of the respiratory tract. The skin and the mucus coating of the epithelium stop microbes from entering the body. The mucus traps them.
(B) Physiological barriers — this matches (IV) Saliva in mouth. These barriers use body fluids to stop microbes from growing. Saliva in the mouth, acid in the stomach and tears from the eyes are examples.
(C) Cellular barriers — this matches (I) Polymorpho-nuclear leukocytes. Certain white blood cells, such as the polymorpho-nuclear leukocytes (neutrophils), engulf and destroy microbes.
(D) Cytokine barriers — this matches (III) Interferons. Cells infected by a virus secrete proteins called interferons. These protect the cells that are not yet infected from the virus.
Note: A similar question was also asked in CUET (UG) 2026 on 06-06-2026 (Slot 1).
NCERT Extract:
Innate Immunity – “… (i) Physical barriers : Skin on our body is the main barrier which prevents entry of the micro-organisms. Mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts also help in trapping microbes entering our body. (ii) Physiological barriers : Acid in the stomach, saliva in the mouth, tears from eyes–all prevent microbial growth. (iii) Cellular barriers : Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. (iv) Cytokine barriers : Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection.”