Immunity — A/L Biology

A. Types of Immunity Definition: Immunity refers to the body's ability to resist and fight against infections and diseases caused by pathogens like bacteria, viruses, and other harmful microorganisms. Explanation: Immunity is the body's defense system that protects against harmful invaders. There are two main types: innate (natural) immunity and adaptive (acquired) immunity. Innate immunity is present from birth and provides immediate but non-specific protection. Adaptive immunity develops after exposure to specific pathogens and provides long-lasting, targeted protection with memory. Think of it as: Think of innate immunity like a castle's basic walls and moat that protect against all invaders, while adaptive immunity is like trained guards who learn to recognize specific enemies and develop better defenses against them. Real-world application: When you get sick with chickenpox once and then never get it again, that's adaptive immunity at work. Your body remembers the virus and knows how to fight it effectively if you're exposed again. B.