Which of the following is a primary way the innate immune system protects the body from disease?

• A. By producing highly specific antibodies against pathogens
• B. By directly mutating pathogen DNA to render them harmless
• C. By generating memory cells for long-term immunity
• D. By providing physical barriers such as skin and mucous membranes

Answer: (D)

Verified step by step guidance

1. Understand that the innate immune system is the body's first line of defense and acts immediately or within hours of an antigen's appearance in the body.
2. Recognize that the innate immune system provides non-specific defense mechanisms, meaning it does not target specific pathogens but rather offers broad protection.
3. Identify the main components of the innate immune system, which include physical barriers (like skin and mucous membranes), chemical barriers, and cellular defenses.
4. Note that physical barriers such as skin and mucous membranes prevent pathogens from entering the body, serving as a primary protective mechanism.
5. Contrast this with the adaptive immune system, which produces highly specific antibodies and memory cells, functions not characteristic of the innate immune system.