Final answer:
Secondary lymphoid tissues, such as lymph nodes, spleen, and lymphoid nodules, are crucial for immune responses as they filter lymph and store lymphocytes, allowing them to encounter and destroy pathogens.
Step-by-step explanation:
Secondary lymphoid tissues, such as lymph nodes, spleen, and lymphoid nodules, play a crucial role in immune responses. They are the sites where activated lymphocytes encounter pathogens or their antigens, leading to the production of antibodies and the destruction of specific pathogens. These tissues filter lymph and store lymphocytes, making them important components of the immune system.