Lymphoid organs are classified into primary (where immune cells develop) and secondary (where immune responses occur). Kupffer cells are liver macrophages that help clear pathogens from the blood.
Step 1: Understanding the Terms Each item in List-1 represents a specific type of biological structure, while List-2 provides corresponding components.
Step 2: Matching the Terms Correctly - Primary lymphoid organ refers to organs responsible for the production and maturation of immune cells. The Bursa of Fabricius (II) is a primary lymphoid organ in birds. - Secondary lymphoid organ includes sites where immune responses occur. Tonsils (IV) are secondary lymphoid organs. - Mononuclear phagocytes include cells that engulf pathogens. Kupffer cells (I) are liver macrophages and belong to this category. - Auxiliary cells support immune responses, and Mast cells (V) play a role in allergic reactions. Step 3: Conclusion Thus, the correct matching is: - A → II - B → IV - C → I - D → V
