71) Which describes best something that the Pathogenscausing Tuberculosis (Mycobacterium tuberculi) Malaria(Plasmodium falciparum) and Sleeping sickness(Trypanosoma cruzi) all have in common?

1. The immune system of a healthy patient can easily clear aninfection of each
2. Each is capable of using gene switching to evade the immunesystem of even a healthy patient
3. None of these

72) B cells and T cells areboth

1. Lymphocytes
2. B Leukocytes
3. Cells of the renal medulla for the kidney

73) B cells are screened for self reactivity inthe

1. Thymus
2. Bursa Bone Marrow
3. Brain
4. Liver

74) T cells are screened for self reactivity inthe

     A)Thymus

B) Bone Marrow

      C) Brain

D) Liver

75) Cytokines are_________

A) Molecules that control homeostasis

B) Molecules that control hormone levels

C) Molecules released by Leukocytes (Macrophages and Dendriticcells) to activate and attract Lymphocytes

D) None of these

76) Each Antigen contains multiple epitopes

1. True
2. False

77) Each B or T cell lymphocyte contains many copies ofthe same Antibody

A) True

B) False

78) Which portion of an Antibody binds theepitope

1. The constant region
2. The variable region
3. The transmembrane region
4. None of these

79) The basic structures of antibodies for B and T cellsare different

1. True
2. False

80) Which type of lymphocyte secretes extracellularantibodies?

1. B cells
2. T cells
3. MHC1              
4. D) Liver cells