Distinguish innate and adaptive immunity.

• A. Innate immunity uses memory; adaptive immunity is immediate and non-specific.
• B. Innate immunity provides immediate, non-specific defense; adaptive immunity targets specific pathogens with memory via T and B cells.
• C. Adaptive immunity is present at birth and innate develops later
• D. Both immune systems have identical functions

Answer: (B)

Understanding how innate and adaptive immunity differ. Innate immunity provides immediate, non-specific defense; adaptive immunity targets specific pathogens with memory via T and B cells. Innate defenses act quickly and broadly, using barriers like skin and mucous membranes and cells such as neutrophils and macrophages, plus the complement system and natural killer cells. They do not recognize specific pathogens and do not form lasting memories. Adaptive immunity is specific to particular antigens and relies on T cells and B cells that recognize those antigens, producing targeted responses such as antibodies and cytotoxic actions, and forming memory cells for faster, stronger responses upon re-exposure. The other statements either assign memory to innate, claim the adaptive system is immediate and non-specific, or say the two systems have identical functions, all of which don’t fit these fundamental differences.