21. The Immune System

Binding of antigens to receptors of immunocompetent lymphocytes leads to clonal selection. Describe the process of clonal selection. What nonlymphocyte cell is a central actor in this process, and what is its function?

Multiple ChoiceMore than one choice may apply.Which of the following antibody capabilities causes a transfusion reaction with A or B erythrocyte antigens?a. Neutralizationb. Precipitationc. Complement fixationd. Agglutination

Which of the following statements is characteristic of a secondary humoral response?

A vaccination works to establish __________.

Which of the following is NOT a mechanism of antibody action?

Which of the following is a characteristic of a secondary immune response?

Which of the following is not involved in the activation of a B cell?a. antigen,b. helper T cell,c. cytokine,d. cytotoxic T cell.

Humoral immunity is provided by __________.

Ted finds out that he has been exposed to measles. He is concerned that he might have contracted the disease, so he goes to see his physician. The physician takes a blood sample and sends it to a lab for antibody levels and titers. The results show an elevated level and activity of IgM antibodies to rubella (measles) virus but very few IgG antibodies to the virus. Has Ted contracted the disease?

Multiple ChoiceMore than one choice may apply.Which of these antibody classes is usually arranged as a pentamer?a. IgGb. IgMc IgAd. IgD