Science MCQs

Memory B and T cells are formed after an initial infection. They remain in the body and provide a much quicker and stronger immune response if the same pathogen is encountered again.

Vaccines contain weakened or dead pathogens or their parts (antigens), which stimulate the adaptive immune system to produce antibodies and memory cells without causing the full-blown disease.

The BCG vaccine is used to prevent Tuberculosis. (OPV is for Polio, DPT is for Diphtheria/Pertussis/Tetanus).

Antibiotics target specific structures or processes in bacteria (e.g. cell wall synthesis). Viruses lack these structures and reproduce inside host cells using the host's machinery, so antibiotics have no effect.

The appendix is believed to act as a safe house for beneficial gut bacteria and may play a role in supporting the immune system by storing immune cells.

T-lymphocytes (T-cells) are responsible for cell-mediated immunity, where they directly attack and destroy infected cells.

Many symptoms of viral infections (fever, aches, fatigue) are actually caused by the body's own immune response as it fights the virus, not by the virus itself.

Hepatitis A is spread through contaminated food and water. Prevention includes vaccination and ensuring access to clean water and proper sanitation.

Inflammation is a non-specific innate immune response that walls off the infected area,, recruits immune cells, and begins the process of tissue repair.

Passive immunity provides immediate, short-term protection because it involves the direct transfer of antibodies, rather than the body producing its own.