Selina Concise Class 7 Biology Solution Chapter No. 7- ‘Allergy’ For ICSE Board Students.
1.) Define the term ‘Allergy’.
Answer: Allergy can be defined as an extra or hypersensitive response to a particular thing. The allergy causes due to the allergen. The allergen can be any dust particle, any unpleasant odor, peanuts, pollen, food also can act as an allergen.
2.) Name the inflammatory chemicals released by basophils causing skin reaction and constriction of the bronchioles.
Answer : the inflammatory chemicals released by basophils causing skin reaction and constriction of the bronchioles are the histamine in case of particularly asthma.
3.) How the allergy causing chemical is naturally removed from the body ?
Answer: Although still worldwide there is no specific cure for allergy, but one can take preventive measures to avoid exposure to allergen. Some drugs or treatment may help to reduce the symptoms.
4.) Match the items given under Column I with those under column II.
Column I Column II
(i) Dust allergy (a) Nuts
(ii) Food allergy (b) Pollen
(iii) Seasonal allergy (c) Asthma
Answer:
Column I Answer
(i) Dust allergy (c) Asthma
(ii) Food allergy (a) Nuts
(iii) Seasonal allergy (b) Pollen
5.) Name any three routes by which allergens normally enter in the body.
Answer: Basically there are many routes to enter the allergen in the body, but worldwide maximum cases of allergy are reported due allergen enter into body via skin, mouth and nose.
6.) What are allergens ? Name any three allergens.
Answer: The allergen is any chemical, drug, unpleasant odor, food such as milk, wheat, nuts, pollen which causes hypersensitive response as compared to normal human. The hypersensitive response includes excessive sneezing, coughing, pain and minor sign and symptoms, are called as allergen.
7.) Name the two tests generally used to diagnose allergy and describe any one of them.
Answer: The two test generally used to diagnose allergy are skin prick test and blood testing.
Blood testing is a simple kind of quantitative test, can be performed on patient of any age. The patient may have certain other diseases also, then also such test can be performed. The blood sample of patient can be collected and analyzed for the concentration of antibodies in plasma.
8.) Which test is mostly favored for testing allergy, prick test or blood test? Why ?
Answer: The test is mostly favored for testing allergy is prick test. It is also called as puncture test. Because in which small pricks with the help of metal or plastic syringe are made on forearm. The various allergens are introduced on skin and inflammation is observed in allergic patients.