Pick blood OR lymph to fill in the following blanks. (1 point)Once T and B cells mature they circulate through the body in(a)_____________ vessels. Dendritic cells that encounter a pathogenin the tissue and became activated traffic to the draining lymphnode via a (b)_____________ vessel. Once a T cell is activated inthe lymph node it enters a (c)____________ vessel to travel andmigrate into the infected tissue.

2. True or False: Tertiary lymphoid organs can form at mucosalsites that have a high exposure to microbes and can activateadaptive immunity. (1 point) a. True b. False

3.Macrophagesanddendriticcellsareinthetissueandnotcirculatinginthebloodstream; what cell present in the blood migrates into the tissue todifferentiate into macrophages and dendritic cells? (1 point) a.Basophils b. Monocytes c. Lymphocytes d. Eosinophils

4. ShortAnswer:Name and describe the shared mechanism thatincreases the diversity of the BCR, antibody and TCR repertoire.Outline the general sequence of events in this mechanism in eitherthe development of antibody producing B cells or T cells thatallows for the diversification of the antigen binding receptors inlymphocytes. (2 points)

5. ShortAnswer:What is the affinity hypothesis for T celldevelopment?Briefly describe 3-4 main outcomes for T cells proposedby this model. (1 point)

6. ShortAnswer:Define central tolerance and peripheral toleranceof B cells to antigen (include location and the overall outcome oftolerance) (2 points).

7. ShortAnswer:Describe two mechanisms of B cell tolerance(include antigen type). Why are these important processes in thedevelopment of B cells? (2 points)