16. Antibodies of the IgG class

A. consist of four subunits
B. are glycoproteins
C. are secreted into the bloodstream
D. all of the above

17. Each IgA antibody molecule consists of

A. four polypeptide chain and has two antigen binding site
B. two polypeptide chain and has one antigen binding site
C. three polypeptide chain and has two antigen binding site
D. two polypeptide chain and has two antigen binding site

18. Antibodies in the human immune system can identify approximately 108 different molecules Which one of the following is correct?

A. This diversity is generated from 108 different immunoglobin genes
B. Many of these molecules are self-antigens
C. Most of these antibodies recognize proteins
D. Most of these antibodies recognize small organic molecules

19. Monoclonal antibodies were first produced by

A. Georges Kohler and Cesar Milstein
B. Sarkar and Sommer
C. Selman Waksman
D. Edward Jenner and Louis Pasteur

20. A polyclonal antibody response

A. is produced only in response to polymeric antigens
B. is produced by several B cells recognizing different pitopes on the same antigen
C. occurs during the lag phase of the immune response
D. violates clonal selection