Question

Which one of the following best describes the innate immune response?

• A. It is an immediate and relatively broad acting response.
• B. It is a delayed response but highly specific.
• C. It is acquired by vaccination.
• D. It is acquired in life.

Hint:

Remember the key differences: \textbf{Innate} = \textbf{In}born, \textbf{I}mmediate, \textbf{N}on-specific. \textbf{Adaptive} = \textbf{A}cquired, \textbf{A}ntigen-specific, has memory.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The immune system has two main branches: the innate immune system and the adaptive immune system. They differ in their speed, specificity, and memory. The question asks for the best description of the innate response.

Step 2: Detailed Explanation:
- Innate Immunity: This is the body's first line of defense. It is present from birth (in-nate). Its key features are: - Immediate: It responds within minutes to hours of pathogen detection. - Broad-acting (Non-specific): It recognizes general patterns common to many pathogens (e.g., bacterial cell wall components) rather than specific antigens. - No memory: It responds in the same way to repeated exposures to the same pathogen. - Adaptive Immunity: This is the second line of defense. - Delayed: It takes several days to develop a response upon first exposure. - Highly specific: It recognizes and targets specific antigens. - Has memory: It mounts a faster and stronger response upon subsequent exposures to the same pathogen. This is the basis for vaccination. - Analyzing the options: - (A) "Immediate and relatively broad acting" perfectly describes innate immunity. - (B) "Delayed response but highly specific" describes adaptive immunity. - (C) and (D) "Acquired by vaccination" and "acquired in life" are features of adaptive immunity.
Step 3: Final Answer:
The best description for the innate immune response is that it is immediate and relatively broad acting. Therefore, option (A) is correct.