1. The document presents information about T cells and B cells, including their development, activation, and functions. 2. T cells develop in the thymus gland and have roles in direct killing of infected cells and regulating the immune response. B cells mature in the bone marrow and produce antibodies to help fight pathogens. 3. Activation of both T and B cells involves interaction with antigen-presenting cells and costimulatory signals, leading to cell proliferation and differentiation into effector and memory cells.