11. What are the solutions prepared from weakened or dead microorganisms, viruses, or toxins that provide some immunity from diseases?

A. Vaccines
B. Histamines
C. Drugs
D. Antibiotics

12. During exposure to a foreign invader, there are more __________ present in the vertebrate body than before exposure

A. antibodies
B. lymphocytes
C. macrophages and antigens
D. all of these

13. To elicit the best antibodies to mouse MHC I, it should be injected into a

A. goat
B. mouse of the same genetic background (strain)
C. mouse of a different strain
D. rat

14. To detect a humoral immune response to influenza virus, it is possible to measure

A. cytotoxicity of virus-infected cells in tissue culture
B. dividing T cells in the draining lymph nodes
C. plasma cytokine levels
D. serum antibody titer

15. Which of the following is in the lymph nodes of a person battling a cold virus?

A. Huge numbers of white blood cells
B. Trapped viruses that have been roaming the body
C. Lymph ducts that enter and exit the nodes and Lymph fluid
D. All of the above