IgD, IgE, and IgG have a monomer shape. IgM has a pentamer shape and IgA has a dimer shape.

Macrophage, dendritic cells, and neutrophiles are major phagocytic cells. Eosinophils are minor phagocytic cells. Basophils secrete histamine and anticoagulant heparin to damaged tissues or allergic reactions.

Humoral immunity, such as memory B cells and antibodies, are types of specific immunity (adaptive immunity).

The rest of the above tissues except A are peripheral lymphoid tissues. Thymus and bone marrow are central lymphoid tissues.