Final answer:
B-1 cells are expressed before B-2 cells, produce antibodies of limited diversity, and do not form memory cells. They contribute to the early immune response with more generalized antibodies.
Step-by-step explanation:
The student is asking about B-1 cells and their characteristics compared to B-2 cells, specifically regarding their expression time, ability to produce memory cells, and the diversity and affinity of the antibodies they produce.
B-1 cells are expressed before B-2 cells, and they produce antibodies (Abs) of limited diversity and low affinity; however, they do not produce memory cells.
In terms of B cells and their functions, there are different subsets, including B-1 and B-2 cells. B-1 cells contribute to the body's early immune response, expressing before B-2 cells, and producing antibodies that are more generalized and have lower affinity compared to the more refined antibodies produced later by B-2 cells. This is due to B-1 cells' restricted variation in their antibody repertoire, which is a result of limited diversity in their antigen-binding sites. Moreover, B-1 cells differ from B-2 cells in that they typically do not form memory cells. Memory cells are, instead, long-lived cells that remain in the body after an initial infection to provide a quicker and more effective response upon re-exposure to the same pathogen. These memory cells are formed during a primary immune response, as shown in Figure 21.23, describing the clonal selection of B cells, which includes the differentiation of plasma B cells that secrete antibodies and memory B cells that retain the pathogen information.
It is important to clarify a misconception in the reference provided: Naive T cells do not produce antibodies; rather, they are involved in the cell-mediated immune response, while naive B cells, upon activation, differentiate into plasma cells that produce antibodies. Therefore, option c from the student's question is correct - B-1 cells produce antibodies of limited diversity and low affinity - while their capacity to produce memory cells is not supported by the given references.