Answer: Central tolerance (clonal deletion of self-reactive T/B cells in thymus/bone marrow) and peripheral tolerance (anergy, Treg suppression).
- A Producing antibodies that are specifically directed against the body's own self proteins, a process that actually drives autoimmune disease rather than preventing it
- B Central tolerance (clonal deletion of self-reactive T/B cells in thymus/bone marrow) and peripheral tolerance (anergy, Treg suppression)
- C Relying mainly on antibody production with little other contributing mechanism, with little role for clonal deletion in the thymus or bone marrow
- D Relying mainly on the formation of long-lived immunological memory cells, despite memory cells having no role in preventing self-reactivity
Correct answer: B. Central tolerance (clonal deletion of self-reactive T/B cells in thymus/bone marrow) and peripheral tolerance (anergy, Treg suppression)
Explanation: Central tolerance: self-reactive T cells deleted in thymus (negative selection), B cells in bone marrow. Peripheral tolerance: surviving self-reactive cells become anergic or are suppressed by regulatory T cells.
An antibody is Y-shaped, with two identical antigen-binding sites at the tips of the variable regions - each shaped to recognise one specific antigen - while the constant (Fc) region at the base is recognised by immune cells to trigger further responses.
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.