Final answer:
The false statement about plasma cells is that A. they live a long time and function as memory cells. Plasma cells are short-lived and secrete antibodies, while memory cells provide long-term immunity.
Step-by-step explanation:
The question asks which statement concerning plasma cells is false. Among the provided options, the false statement is that plasma cells live a long time and function as memory cells. This is incorrect because, while plasma cells do differentiate from activated B cells and produce antibodies, they are short-lived and do not function as memory cells. Memory B cells are the ones that remain in the body for an extended period, providing long-term immunity by remembering the specific antigen and responding quickly upon subsequent exposures.
Plasma cells are essentially antibody factories, secreting large quantities of antibodies—up to 100 million molecules per hour. These antibodies can remain in circulation for a long time, even after the plasma cells that produced them have perished. Memory B cells are crucial for the immune system's ability to mount a quicker and more potent response upon re-exposure to the same pathogen.