Concept Questions - Chapter 15
Take some time to write answers to these questions.
If you can answer them, you have a good grasp of the material!

1. What function do receptors play in specific immune responses?
How can receptors be made to vary so widely?

2. Describe the major histocompatibility complex, and explain how it participates in immune reactions.

3. Evaluate the following statement: Each different lymphocyte type must have a unique receptor to react with antigen.
How many different Ags might one be expected to meet up with during life?

4. What constitutes a clone of lymphocytes?
Explain the clonal selection theory of antibody specificity and diversity.
During development, when is antigen not needed, and why is it not needed?
When is antigen needed?
Why must the body develop tolerance to self?

5. Trace the development of the B-cell receptor from gene to cell surface.
What is the structure of the receptor?
What is the function of the variable regions?

6. Trace the origin and development of B lymphocytes; of T lymphocytes.
What is happening during lymphocyte maturation?

7. Describe three ways that B cells and T cells are similar and at least five major ways in which they are different.

8. What is an antigen or immunogen?
What is the antigenic determinant?
How do foreignness, size, and complexity contribute to antigenicity?
What is a mosaic antigen?
Why are haptens by themselves not antigenic, even though foreign?
How can they be made to behave as antigens?

9. Differentiate among autoantigens, alloantigens, and heterophile antigens.
Explain briefly what importance each has in immune reactions.

10. Describe the actions of an antigen-processing cell.
What is the difference between a T-cell-dependent and T-cell-independent response?

11. Trace the immune response system, beginning with the entry of a T-cell-dependent antigen, antigen processing, presentation, the cooperative response among the macrophage and lymphocytes, and the reactions of activated B and T cells.

What are the actions of interleukins-1 and -2?

12. On what basis is a particular B-cell clone selected?
How are B cells activated, and what events are involved in blast formation?
What happens when B cells are activated?
What are the functions of plasma cells, clonal expansion, and memory cells?

13. Describe the structure of immunoglobulin.
What are the functions of the Fab and Fc portions?
Describe four or five ways that antibodies function in immunity.
Describe the attachment of Abs to Ags. (What eventually happens to the Ags?)

14. Contrast the primary and secondary response to Ag.
Explain the type, order of appearance, and amount of immunoglobulin in each response and the reasons for them.

What causes the latent period? The anamnestic response?
Explain how monoclonal and polyclonal antibodies are different.
Outline the basic steps in production of monoclonal antibodies.
Describe several possible applications of monoclonals in medicine.

15. Why are the immunities involving T cells called cell-mediated?
How do T cells become sensitized?

Summarize the function of each category of T cell and the types of receptors with which they are associated. Define cytokines, and provide some examples of them.
How do cytotoxic cells kill their target?
Why would the immune system naturally require suppression?
What is a natural killer cell, and what are its functions?

16. Contrast active and passive immunity in terms of how each is acquired, how long it lasts, whether memory is triggered, how soon it becomes effective, and what immune cells and substances are involved.
Name at least two major ways that natural and artificial immunities are different.

17. Multiple matching (summarizes information from chapters 14 and 15).
In the blanks on the left place the letters of all of the host defenses and immune responses in the right column that can fit the description.

Return to Ch.15 Activities l Online Learning Center