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Human Health and Disease — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease1 Mark
Question

For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.

Assertion : Allergy is an immunity disorder.

Reason: Allergy is confined to a person only.

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Answer

  1. Both assertion and reason are true, but reason is not the correct explanation of assertion.

Explanation: 

Allergy is non-infectious unusual reaction or hypersensitivity of an individual to a foreign substance or agent that may be harmless to other individuals (thus it is considered as immunity disorder). It is non-communicable as it is confined to a person only and does not spread from one person to another. The foreign substance or allergen on first contact functions as mild antigen. It produces antibodies which remain attached with the mast cell. Lysis of mast-cells occur, which releases histamine as allergy mediator.

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