Final answer:
Defective lymphocytes that can't recognize self cells are eliminated in the bone marrow and thymus, which are crucial for lymphocyte development and preventing autoimmune reactions.
Step-by-step explanation:
Defective lymphocytes that can't distinguish between self and non-self cells are eliminated in the primary lymphoid organs, specifically the bone marrow for B cells and the thymus for T cells. These organs play a critical role in lymphocyte development, where immature lymphocytes undergo a selection process to ensure they can recognize self-antigens and not attack the body's own cells.
Lymphocytes that do not pass this selection process are eliminated to prevent autoimmune reactions. This process is a crucial aspect of the adaptive immune system's ability to distinguish self from non-self, which ensures that immune responses are directed only against pathogens.