Health & Disease: 15 MCQs with answers

Mucous membranes trapping pathogens

Mucous membranes act as physical barriers and are part of innate (non-specific) immunity, while the other options involve specific adaptive immune responses.

To stimulate the immune system to produce memory cells

Vaccines contain antigens that trigger an adaptive immune response, leading to the formation of memory B and T cells for long-term protection.

They provide a rapid and stronger response upon re-exposure to the same antigen

Memory cells are formed after initial exposure to an antigen and enable a faster, more effective immune response upon subsequent exposures.

Tobacco smoking

Tobacco smoke contains carcinogens that can cause mutations in DNA, leading to cancer.

Thymus

The thymus is the primary lymphoid organ where T lymphocytes mature and undergo selection.

True

Vaccination stimulates the immune system to produce antibodies and memory cells, resulting in active acquired immunity.

Passive natural immunity

Antibodies are transferred naturally from mother to fetus, providing passive immunity without the fetus producing its own antibodies.

They lack contact inhibition

Cancer cells lose contact inhibition, allowing them to divide uncontrollably and invade other tissues.

Vaccination with a weakened pathogen

Vaccination with a weakened pathogen stimulates the immune system to produce its own antibodies and memory cells, which is active artificial immunity.

T lymphocytes

T lymphocytes, especially cytotoxic T cells, mediate the cell-mediated immune response by directly attacking infected or abnormal cells.

BCG vaccine

BCG is a live attenuated vaccine derived from Mycobacterium bovis, used against tuberculosis.

Passive artificial immunity

Antivenom contains pre-formed antibodies from another animal, providing immediate but temporary passive artificial immunity.

They can metastasize to distant sites

Malignant tumors are cancerous and can invade nearby tissues and spread (metastasize) to other parts of the body.

False

Cancer cells often evade the immune system by downregulating MHC molecules or producing immunosuppressive factors, but they typically do not produce self-antigens; instead, they may express tumor-specific antigens that can be recognized.

They interfere with viral replication and activate immune cells

Interferons are signaling proteins released by virus-infected cells that interfere with viral replication and enhance the immune response.