Final answer:
Humoral immunity is provided by antibodies, which are produced by plasma cells that have matured from B cells. B cells focus on extracellular pathogens, while T cells handle infected cells, providing cellular immunity.
Step-by-step explanation:
Humoral Immunity
Humoral immunity is provided by antibodies. Antibodies are specific proteins produced as a response to antigens, and they play a central role in the immunity against extracellular pathogens. They are formed by B cells, which are a type of white blood cells. Specifically, B cells mature into plasma cells that generate antibodies designed to target and neutralize specific antigens.
Cellular immunity, on the other hand, is mediated by T cells and deals with intracellular pathogens like viruses that have already infected cells. While B cells are responsible for the production of antibodies in humoral immunity, T cells provide cellular immunity by directly attacking infected cells or assisting other immune cells.
To answer the multiple-choice component, the correct statement in the list is that antibodies are produced by plasma cells. Therefore, option 1) complement proteins, 3) interferons, and 4) T cells are not directly responsible for humoral immunity.