Allergy, with symptoms such as sneezing, watery eyes, running nose and difficulty in breathing, is due to the release of which chemicals from the mast cells?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Histamine and serotonin
Allergy is the exaggerated response of the immune system to certain antigens in the environment, such as mites in dust, pollens and animal dander. These antigens are called allergens, and the antibodies made against them are of the IgE type. The symptoms come from chemicals that the mast cells release.
Option (1) Histamine and serotonin — Correct. Mast cells release histamine and serotonin, and these chemicals cause sneezing, watery eyes, running nose and difficulty in breathing.
Option (2) Adrenalin and steroids — Incorrect. Adrenalin and steroids are drugs used to treat allergy. They quickly reduce the symptoms; they do not cause them.
Option (3) Interferons and IgA antibodies — Incorrect. Interferons are proteins given out by virus-infected cells to protect non-infected cells. IgA is one type of antibody. Neither is the chemical that mast cells release in allergy.
Option (4) IgE antibodies and anti-histamines — Incorrect. IgE antibodies are made by the immune system against allergens; they are not released by mast cells. Anti-histamines are drugs that reduce the symptoms of allergy.
NCERT Extract:
Allergies – “… The exaggerated response of the immune system to certain antigens present in the environment is called allergy. The substances to which such an immune response is produced are called allergens. The antibodies produced to these are of IgE type. Common examples of allergens are mites in dust, pollens, animal dander, etc. Symptoms of allergic reactions include sneezing, watery eyes, running nose and difficulty in breathing. Allergy is due to the release of chemicals like histamine and serotonin from the mast cells.”