Answer: To stimulate immune memory without causing disease, so the body can respond faster to future infection.
- A To directly kill any bacteria that are already circulating in the bloodstream using strong chemical agents
- B To stimulate immune memory without causing disease, so the body can respond faster to future infection
- C To directly supply the body with a temporary dose of ready-made antibodies against one disease
- D To permanently and substantially increase the total circulating white blood cell count in the body
Correct answer: B. To stimulate immune memory without causing disease, so the body can respond faster to future infection
Explanation: Vaccination introduces antigens (weakened pathogen, killed pathogen, or protein subunit) to stimulate an immune response and create memory B and T cells. On future exposure to the real pathogen, the immune system responds rapidly and powerfully.
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.