LIFE SCIENCE

Detailed explanation-1: -In addition to “fighting off” these pathogens, active immunity is important because it lasts a long time in the form of immunologic memory. Immunologic memory consists of B and T cells that can recognize a particular pathogen (see “Adaptive immune system").

Detailed explanation-2: -Immunological memory is a unique property of the immune system as it can “store” information about a stimulus and can mount an effective response when the stimulus is encountered again. This response – a secondary immune response – is quicker and stronger than the primary response.

Detailed explanation-3: -Memory is a characteristic recognized within both the innate and adaptive arms of the immune system. Although the mechanisms and properties through which innate and adaptive immune memory are induced are distinct, they collude to improve host defense to pathogens.