IMMUNOLOGY

Detailed explanation-1: -B lymphocytes, also called B cells, create a type of protein called an antibody. These antibodies bind to pathogens or to foreign substances, such as toxins, to neutralize them. For example, an antibody can bind to a virus, which prevents it from entering a normal cell and causing infection.

Detailed explanation-2: -The secondary lymphoid organs are sites where naïve lymphocytes are activated, and include lymph nodes, spleen and mucosal-associated lymphoid tissue, such as Peyer’s patches in the small intestine.

Detailed explanation-3: -Active immunity utilizes cytotoxic T lymphocytes, TH1, TH2 cells, and activated B cells to target infections from multiple angles. CTLs destroy infected cells, and the immunoglobulins produced by B cells target antigens in the bloodstream to bind and prevent them from reaching their target cells.