Final answer:
The statement that there is a small proportion of antigen-specific T cells in the germinal center is true. T cells provide help to B cells in the germinal center, and MHC II is not found on most body cells but on specific immune cells. Moreover, activated B cells produce antibodies, unlike activated T cells, involved in cell-mediated immunity.
Step-by-step explanation:
In reference to whether antigen-specific T cells are present in the germinal center, the statement is true. The germinal center is an area within secondary lymphoid organs where mature B cells proliferate, differentiate, and mutate their antibody genes through a process known as somatic hypermutation. During this process, T cells, including a small proportion of antigen-specific T cells, provide essential help to B cells. CD4+ T cells, also known as helper T cells, interact with B cells and aid in their selection and maturation.
Regarding the information provided about T cells, the false statement is: "C. MHC II is a receptor found on most body cells, while MHC I is a receptor found on immune cells only." In fact, MHC I molecules are found on nearly all nucleated cells, while MHC II molecules are primarily expressed on professional antigen-presenting cells such as dendritic cells, macrophages, and B cells.
Additionally, naïve B and T cells are indeed lymphocytes that have not yet encountered their specific antigen, while activated B cells produce antibodies during the humoral immune response and activated T cells are involved in cell-mediated immunity, not in the direct production of antibodies.