Final answer:
Most antibodies belong to the gamma globulin fraction of serum proteins and are crucial for the body's immune response.
Step-by-step explanation:
Most antibodies are in the gamma globulin fraction of serum proteins. Antibodies, also known as immunoglobulins, are produced by specialized leukocytes called plasma cells, and they play a critical role in the body's immune response by binding to foreign objects such as bacteria and viruses. Unlike other plasma proteins produced predominantly by the liver, immunoglobulins are a heterogenous group of proteins accounting for approximately 20% of the total plasma proteins, crucial in recognizing and reacting to antigens. Gamma globulins are a part of the globulin protein class which makes up about 38% of the total plasma protein volume, with clinical levels typically ranging from 1.0-1.5 g/dL of blood.