LabCE

Question 1

Two biologically functional characteristics of immunoglobin G (IgG) are:

A.) First effective defense against bacteria; activation of the classical complement pathway.
B.) Opsonization of antigens for phagocytosis by macrophages and neutrophils; neonatal immunity by transfer of maternal antibodies across the placenta and gut of the fetus.
C.) Mucosal immunity, defends external body surfaces.
D.) Provides protection against parasitic helminithic infection; mediates the release of histamines and heparin from mast cells and basophils.

Answer 1

B.) Opsonization of antigens for phagocytosis by macrophages and neutrophils; neonatal immunity by transfer of maternal antibodies across the placenta and gut of the fetus.

• Opsonization of antigens for phagocytosis by macrophages and neutrophils; neonatal immunity by transfer of maternal antibodies across the placenta and gut of the fetus are hallmark characteristics of IgG. In addition, it is the predominant antibody class in plasma or serum and combats microorganisms and their toxins in extravascular fluid.
• IgM is the first effective defense against bacteria; activation of the classical complement pathway.
• IgA functions in mucosal immunity to defend external body surfaces.
• IgE provides protection against parasitic helminthic infection; mediates the release of histamines and heparin from mast cells and basophils.