The innate immune system provides the body with its first line of defense against foreign substances.

• A. True
• B. False
• C. It depends
• D. Not sure

Answer: (A)

The innate immune system provides the body with its first line of defense against foreign substances. It offers immediate, non-specific protection through physical barriers like skin and mucous membranes, chemical barriers such as acidic environments and antimicrobial enzymes, and cellular responses from neutrophils and macrophages, plus inflammation that helps contain invaders. These defenses are always present and act quickly without requiring prior exposure, so they serve as the initial shield before any tailored, adaptive responses develop. The adaptive system comes in later, providing targeted attacks and memory after exposure. So the statement is true.