Question

Define immunity. Differentiate between innate and acquired immunity with suitable examples.

Hint:

Innate immunity = present by birth (non-specific); Acquired immunity = developed later (specific and has memory).

Answer 1

Definition: Immunity is the ability of an organism to resist or defend itself against diseases caused by pathogens or harmful substances. It is the body's defense mechanism to maintain health. Types of Immunity: \begin{enumerate} \item Innate Immunity: - Present from birth. - Non-specific defense mechanism that acts immediately against pathogens. - Examples: skin barrier, phagocytic cells (macrophages), inflammation, lysozyme in saliva. \item Acquired Immunity (Adaptive Immunity): - Develops during lifetime after exposure to pathogens or vaccines. - Specific defense mechanism; provides memory against future infections. - Involves lymphocytes (B-cells and T-cells). - Examples: immunity after chickenpox infection, vaccination-induced immunity. \end{enumerate} Difference Between Innate and Acquired Immunity:\[\begin{array}{|c|c|} \hline Innate Immunity & Acquired Immunity \\ \hline \text{Present from birth} & \text{Develops during lifetime} \\ \hline \text{Non-specific defense} & \text{Specific defense against particular pathogens} \\ \hline \text{No memory} & \text{Has memory (stronger on second exposure)} \\ \hline \text{Example: skin barrier, phagocytosis} & \text{Example: vaccination, antibody production} \\ \hline \end{array}\]Conclusion: Innate immunity provides immediate protection, while acquired immunity ensures long-term and specific defense against diseases.