Q154 / 180 · AIIMS 2003 · Zoology
Assertion : Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions.
Reason : Allergens in the environment on reaching human body stimulate mast cells in certain individuals.
- Correct answerAIf both Assertion and Reason are true and the reason is the correct explanation of the assertion
- BIf both Assertion and Reason are true but the reason is not the correct explanation of the assertion
- CIf Assertion is true statement but Reason is false
- Dif both Assertion and Reason are false statements
Solution
Mast cells act on body's defense mechanism. When some allergens like different pollutants, smog, smoke, pollen grains etc. come in contact with mast cell, they stimulate the mast cells. The allergic reaction is triggered by cross linking of $\operatorname{Ig} \mathrm{E}$ molecules on the surface of mast cells by allergen. And ultimately mast cells release excessive amounts of inflammatory chemicals which cause allergic reactions.
Hence, the correct answer is option: 'A'.