Which of the following is NOT a barrier under innate immunity?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. Mental barriers.
Innate immunity is the body’s natural defense system present from birth. It includes physical barriers like the skin and mucous membranes, chemical barriers such as stomach acid and enzymes, and biological components like phagocytic cells and natural killer cells. These mechanisms respond quickly to pathogens in a general, non-specific way. However, mental barriers are not related to the immune system at all. They refer to psychological or cognitive blocks that affect thinking or behavior, not physical or biological defenses against disease. Therefore, mental barriers are not a component of innate immunity, making them the correct answer in this context.