Final answer:
B cells and plasma cells are part of the humoral immune system which produces antibodies, while helper, cytotoxic, and suppressor cells are involved in cell-mediated immunity.
Step-by-step explanation:
The humoral immune system is a part of the adaptive immune system that involves B cells and antibody production. Based on the information provided, the cells that belong to the humoral immune system are:
B Cell: B cells are responsible for producing antibodies that target specific antigens.
Plasma Cell: Plasma cells are a type of activated B cell that secrete large amounts of antibodies into the bloodstream to help fight off pathogens.
Therefore, the correct answer is (c) 1 and 4 only.
The parts of the humoral immune system include B cells and plasma cells. B cells are responsible for producing antibodies, and when they become activated by an antigen, they differentiate into plasma cells which secrete antibodies. Therefore, the answer to which of these are part of the humoral immune system is c) 1 and 4 only. Helper cells, cytotoxic cells, and suppressor cells are all types of T cells, which play roles in cell-mediated immunity rather than humoral immunity.