Final answer:
The conversion of B cells to plasma cells during an immune response is a part of adaptive immunity. Activated B cells differentiate into antibody-secreting plasma cells, which are critical in the body's defense against pathogens. Memory cells, a type of long-lived plasma cell, quickly produce large amounts of antibodies upon reexposure to a pathogen.
Step-by-step explanation:
The conversion of B cells to plasma cells over a course of several hours to days is known as B cell differentiation or plasma cell differentiation. When B cells are activated by binding to an antigen, they undergo clonal proliferation, and their daughter cells differentiate into plasma cells. These are specialized cells that act as antibody factories, secreting large quantities of antibodies. Plasma cells often migrate back to the bone marrow after leaving the secondary lymphoid organs, continuing to secrete antibodies for a specific period before they die. This differentiation process is associated with adaptive immunity and is crucial for the body's defense against pathogens.
During the primary response to infection, the first antibodies secreted come from plasma cells. Upon reexposure to the same pathogen, memory cells, which represent long-lived plasma cells, will readily differentiate into antibody-secreting plasma cells that output a significantly higher amount of antibodies and for a longer period of time compared to the primary response. This is part of the adaptive immune system's memory, which allows for a quicker and more robust response upon subsequent encounters with the same pathogen.