True or False: Immune disorders are always associated with an overactive immune system.

Explanation: Numerous scientific studies have found no link between vaccines and autism. The notion that vaccines cause autism was based on a discredited and fraudulent study, and subsequent research has shown no evidence of such a link.

Explanation: B cells are a type of lymphocyte that plays a crucial role in the immune response by recognizing and binding to specific antigens. When a B cell encounters an antigen that matches its specific receptor, it becomes activated and differentiates into plasma cells, which produce antibodies against the antigen.

Incorrect choices:

b. Cytotoxic T cells are responsible for directly attacking and killing infected or abnormal cells during cell-mediated immunity. They do not primarily recognize antigens during the immune response.

c. Macrophages are antigen-presenting cells that engulf and process pathogens to present their antigens to other immune cells, such as T cells and B cells. While they are involved in antigen recognition, they are not the primary cells responsible for this function.

d. Red blood cells do not have a direct role in antigen recognition or the immune response. Their primary function is to transport oxygen throughout the body.