Which of the following statements best describes the role of lymphocytes in the immune system?

• A. Lymphocytes secrete antibodies, coordinate action of other immune cells, and serve in immune memory.
• B. Lymphocytes are primarily involved in phagocytosis and the release of inflammatory mediators.
• C. Lymphocytes form physical barriers to prevent pathogen entry into the body.
• D. Lymphocytes produce complement proteins that directly lyse pathogens.

Answer: (A)

Verified step by step guidance

1. Understand that lymphocytes are a type of white blood cell crucial to the adaptive immune response.
2. Recall that lymphocytes include B cells and T cells, each with distinct functions: B cells produce antibodies, while T cells help coordinate immune responses and kill infected cells.
3. Recognize that lymphocytes are involved in immune memory, allowing the body to respond more rapidly and effectively upon subsequent exposures to the same pathogen.
4. Eliminate options that describe functions not primarily associated with lymphocytes, such as phagocytosis (mainly by macrophages and neutrophils), forming physical barriers (role of skin and mucous membranes), and producing complement proteins (produced mainly by the liver).
5. Conclude that the best description of lymphocyte function is their role in secreting antibodies, coordinating other immune cells, and serving in immune memory.