Which statement describes the innate immune system?

• A. Immunity present from birth, heredity, congenital
• B. Immunity developed after exposure to pathogens
• C. Highly specific and retains memory
• D. Requires vaccination to develop

Answer: (A)

Innate immunity is the body's immediate, non-specific defense that you’re born with. It comes from genetic inheritance and is present congenitally, not learned or acquired after exposure. This system provides rapid protection through barriers like skin and mucous membranes, as well as innate immune cells and complement, but it does not tailor responses to specific pathogens and it doesn’t form memory of past encounters. That’s why the statement describing immunity present from birth, inherited, congenital best fits the innate system. By contrast, immunity developed after exposure, high specificity with memory, and vaccine-driven protection are all hallmarks of adaptive (acquired) immunity, which builds through encounters with pathogens and targeted responses over time.