Define the following terms: Allergy and Cell-mediated immunity.

(N/A) Allergy: It is an exaggerated or hypersensitive immune response to certain antigens present in the environment,such as dust,pollen,or animal dander. This response involves the release of chemicals like histamine and serotonin from mast cells.
Cell-mediated immunity $(CMI)$: This is an immune response that does not involve antibodies. Instead,it involves the activation of phagocytes,antigen-specific cytotoxic $T$-lymphocytes,and the release of various cytokines in response to an antigen. It is primarily responsible for the rejection of transplanted organs and defense against intracellular pathogens like viruses and certain bacteria.