Memory cells enable long-term immunity in B- and T-lymphocytes

Steps:

• Recall that B- and T-lymphocytes are key to adaptive immunity, recognizing specific antigens via receptors.
• Evaluate each option against lymphocyte functions: activation, cloning, memory, and cytokine roles.
• Identify that memory cell production is a shared, accurate feature for both cell types.
• Confirm C matches this, while others misstate processes.

Why C is correct:

• Memory cells are long-lived B- and T-lymphocytes that persist after initial antigen exposure, enabling faster, stronger responses upon re-exposure, as defined in adaptive immunity.

Why the others are wrong:

• A: Activation requires antigen binding plus co-stimulation signals, not just receptor binding alone.
• B: Cloning occurs after activation, not directly from antigen-receptor meeting.
• D: Cytokines are released mainly by T-lymphocytes to regulate immunity, but B-lymphocytes produce antibodies, not primarily cytokines for antibody release.

Final answer: C