Although mutants incapable of producing exotoxins are relatively easy to isolate, mutants incapable of producing endotoxins are much harder to isolate. From what you know of the structure and function of these types of toxins, explain the differences in mutant recovery.

What is the origin of the phagocytes and lymphocytes active in the immune response? Track the maturation of B cells and T cells.

How do Th cells differ from Tc cells? Differentiate between the functional roles of Th1, Th2, Th17, and Treg cells.

Describe the potential problems that would arise if a person had an acquired inability to phagocytose pathogens. Could the person survive in a normal environment such as a college campus? What defects in the phagocyte might cause lack of phagocytosis? Explain.

Specificity and tolerance are necessary qualities for an adaptive immune response. However, memory seems to be less critical, at least at first glance. Define the role of immune memory and explain how the production and maintenance of memory cells might benefit the host in the

Why is the immunoblot (Western blot) procedure used to confirm screening tests that are positive for human immunodeficiency virus (HIV)?

Describe the mode of action of a ?-lactam antibiotic. Why are these antibiotics generally more effective against gram-positive bacteria than against gram-negative bacteria?

Distinguish between the modes of action of three of the protein synthesis–inhibiting antibiotics.

How does herd immunity protect the nonimmune members of the population from acquiring a disease? Will herd immunity work for diseases that have a common source, such as water? Why or why not?

Give examples of host- to- host transmission of disease via direct contact. Also give examples of indirect host- to- host transmission of disease via vector agents and fomites.