All immunoglobulins, regardless of their type (e.g., IgG, IgM, etc.) have a common structure. They are polypeptides (denoted by the amino and carboxyl ends) and resemble the letter "Y" (featured below).
Region 1 represents the "head region" (amino) of the antibody.
Region 2 represents the "tail region" (carboxyl) of the antibody.
Region 3 represents both heavy chains (light blue/dark blue/purple) with one variable and one constant domain (segment of the protein chain).
Region 4 represents the two (light-green/dark-green and light-green/blue ) light chains attached to the heavy chain with disulfide bonds. These chains also contain one variable and one constant domain (segment of the protein chain).
Region 5 represents the amino end of both light and heavy chains.
Region 6 represents the hinge region that connects either heavy chain in the middle of the protein.
Which of the following statements accurately describes the structure and/or function of the antibody (AKA immunoglobulin)?