Final answer:
The lifespan of plasma cells is approximately several days, but memory cells can live much longer, possibly even the lifetime of the individual.
Step-by-step explanation:
The lifespan of plasma cells is approximately several days. Plasma cells are specialized white blood cells that secrete antibodies and are essential for the body's immune response. Upon the first exposure to a pathogen, plasma cells are formed from B cells and secrete antibodies. These plasma cells have a relatively short lifespan, typically living just for a few days. However, some plasma cells, known as memory cells, can survive for much longer and even for the lifetime of the individual. Memory cells retain information about specific pathogens, enabling a quicker and more effective immune response upon subsequent exposures to the same pathogen. Plasma cells that are part of this secondary response produce a greater amount of antibodies for a longer period.