Immunology LabBio 242 Anatomy and Physiology IIImmune System: Common Characteristics of B and T Cells1. Shared features of B and T lymphocyte function include:a. ___________________________________________________________________________________b. ___________________________________________________________________________________c. ___________________________________________________________________________________d. ___________________________________________________________________________________2. Lymphocytes must distinguish between normally occurring internal antigens called _________________________ and those external to the body. The ability to distinguish between the pathogens depends on the ______________ of the lymphocyte antigen receptors.3. Specificity of B and T cells depends on their ability to recognize ___________ ______________. They have the ability to do this because their surface is covered with 10,000 to 100,000 __________________________ receptors. All of these receptors on a specific B cell are identical; thus, thecells bind optimally with only one _______________________.4. The antigen receptor on a B cell is an immunoglobulin, which is Y-shaped and basically a membrane-bound ______________ .5. The T cell receptor recognizes antigen fragments housed in cell membrane proteins called “_________________________” (_______) proteins.6. The immune system can develop receptors for a specific antigen before that antigen enters the body. Lymphocytes make a wide variety of receptors, and when an antigen binds and activates one of these receptors, the cell divides, making many ______________. This process is called _________________________.7. Our bodies make approximately ______________ different types of lymphocyte antigen receptors. With only 25,000 different genes in our body, how can so many antigen receptors be made?____________________________________________________________________________8. Receptors have two regions. The ______________ region is the same for all antigen receptors, whereas the______________ region is specific for an antigen.9. The ______________ and ______________ are primary lymphoid organs because the B and T cells originate and/or mature in these organs. To become immunocompetent, B and T cells must accomplish:1. ___________________________________________________________________________________2. ___________________________________________________________________________________10. Immature T cells migrate to the thymus. In the outermost cortex they form new _________________________. They then migrate to the ______________ to test these new receptors.11. T cells recognize antigens by binding to _______ proteins on an antigen-presenting cell such as a dendritic cell. This process is known as ______________ selection. If T cells fail to recognize this protein, they die by a process known as ______________.12. If a T cell recognizes this protein (the one mentioned above), it is then tested for recognition of _________________________, the body’s own antigens. This process is known as _________________________ selection. Immature T cells that do not recognize the body’s own antigens are called _________________________ and allowed to mature.13. If lymphocytes attack the body’s own cells, this will result in a/an _________________________ disease.14. Below is a list of diseases that result when the immune system attacks the body’s own cells. State what cells the immune system is attacking in each disease.Graves’ disease: _________________________Type I diabetes: _________________________Multiple sclerosis: _________________________Hemolytic anemia: _________________________15. These diseases may occur as a result of what three events mentioned in this Topic?1. ___________________________________________________________________________________2. ___________________________________________________________________________________3. ___________________________________________________________________________________16. ______________ lymphocytes are lymphocytes that have not encountered their one specific antigen. What is the best method for the lymphocyte to find its antigen?____________________________________________________________________________17. The T cell becomes activated when it encounters its antigen. The T cell then undergoes repeated cell division known as _________________________. During this process, two basic types of cells are produced:1. ______________ cells, which attack the antigen-presenting cell2. ______________ cells, which remain to be reactivated if the antigen is ever encountered again18. When an antigen activates a B cell, the cloned _________________________ (effector cells) secrete antibodies in about seven days. This is known as the ______________ immune response.19. When exposed to the same antigen again, the ______________ B cells generate a/an ______________ immune response. This response is generated (faster or slower) and produces a/an ______________ number of effector cells.20. The purpose of _________________________ is to generate memory cells, thus protecting us without the risk of getting