A Level Biology Practice Exam

What are plasma cells?

1. B lymphocytes that produce and release antibodies

2. Platelets that help in blood clotting

3. Red blood cells that carry oxygen

4. Cells that produce insulin in the pancreas

The correct answer is: B lymphocytes that produce and release antibodies

Plasma cells are specialized B lymphocytes that play a crucial role in the immune response by producing and releasing antibodies. When B cells encounter an antigen, they can differentiate into plasma cells, which are specifically tailored to produce large quantities of antibodies that bind to that antigen. This antibody production is essential for neutralizing pathogens and marking them for destruction by other immune cells. The nature of plasma cells allows the body to create a specific immune response against pathogens, making them vital in the adaptive immune system. These cells can produce a vast amount of antibodies, often tens of thousands per cell per second, providing a robust defense mechanism against infections. In contrast, the other options refer to different types of cells or functions altogether. Platelets are involved in blood clotting, red blood cells are responsible for oxygen transport, and pancreatic cells produce insulin, which regulates blood sugar levels. Each of these functions is essential to various physiological processes but does not relate to the production of antibodies as plasma cells do.