Problem 12
Cite three reasons why developing a vaccine against HIV infection has been challenging.
Problem 13
What would be the consequences of lacking a. helper T cells? b. cytotoxic T cells? c. \(\mathrm{B}\) cells? d. macrophages?
Problem 14
Explain how the immune system can respond to millions of different nonself antigens using only a few hundred antibody genes.
Problem 15
How are SCID and AlDS similar and different?
Problem 16
What part do antibodies play in allergic reactions and in autoimmune disorders?
Problem 17
What do a plasma cell and a memory cell descended from the same \(\mathrm{B}\) cell have in common? How do they differ?
Problem 18
Why is a deficiency of T cells more dangerous than a deficiency of B cells?
Problem 19
Cite two explanations for why autoimmune disorders are more common in females.
Problem 20
How do each of the following illnesses disturb immunity? a. graft-versus-host disease b. SCID c. scleroderma d. AlDS e. atopic dermatitis
Problem 21
Why is a polyclonal antibody response valuable in the body, but a monoclonal antibody valuable as a diagnostic tool?
