Selina Textbook Solutions: Allergy | Biology Class 7 ICSE PDF Download

 Page 1


Allergy 
Review Questions 
Question 1. 
Define the term “allergy”. 
Answer: 
Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
Question 2. 
Name the inflammatory chemical released by the basophils causing skin reaction and 
construction of the bronchioles. 
Answer: 
The histamine causes inflammation, skin rash and constriction of the bronchioles (as in 
asthma). 
Question 3. 
How the allergy causing chemical is naturally removed from the body ? 
Answer: 
There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
4. Match the items given under column I with those given under column II. 
column I                                         column II 
 
Answer: 
              column I                                         column II 
Page 2


Allergy 
Review Questions 
Question 1. 
Define the term “allergy”. 
Answer: 
Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
Question 2. 
Name the inflammatory chemical released by the basophils causing skin reaction and 
construction of the bronchioles. 
Answer: 
The histamine causes inflammation, skin rash and constriction of the bronchioles (as in 
asthma). 
Question 3. 
How the allergy causing chemical is naturally removed from the body ? 
Answer: 
There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
4. Match the items given under column I with those given under column II. 
column I                                         column II 
 
Answer: 
              column I                                         column II 
 
Question 5. 
Name any three routes of which allergens normally enter in our body. 
Answer: 
1. Skin — Substances that come into contact with the skin, such as latex, are also 
common causes of allergic reactions, known as contact dermatitis or eczema. 
2. Mouth — A wide variety of foods can cause allergic reactions, but 90% of allergic 
responses to foods’are caused by cow’s milk, soy, eggs, wheat, peanuts, tree 
nuts, fish and shellfish. 
3. Nose — Pollen, spores, dust particles and certain chemicals find entry through the 
nose. 
Question 6. 
What are allergens ? Name any three allergens. 
Answer: 
The substances that cause allergies are called allergens. 
1. Dust particles 
2. Nuts 
3. Pollen 
Question 7. 
Name the two tests generally used to diagnose allergy and describe any one of them. 
Answer: 
1. Prick Test—Skin prick test is also known as “puncture testing” or “prick testing” 
due to the series of tiny punctures or pricks made into the patients skin. A small 
plastic or metal device is used to puncture or prick the skin. Sometimes, the 
allergens are injected intradermally into the patients skin, with a needle and 
syringe. Small amounts of suspended allergens or their extracts (e.g., pollen grain, 
insect sting proteins, peanut extracts) are introduced to sites on the skin marked 
with pen or dye. Common areas for testing include the inside of forearm and the 
back. 
2. Blood Testing — A sample of the patient’s blood is sent to a laboratory for 
analysis. Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The 
quantitative allergy blood result can help determine what a patient is allergic to, 
help predict and follow the disease development, estimate the risk of a severe 
reaction, and explain cross-reactivity. 
Page 3


Allergy 
Review Questions 
Question 1. 
Define the term “allergy”. 
Answer: 
Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
Question 2. 
Name the inflammatory chemical released by the basophils causing skin reaction and 
construction of the bronchioles. 
Answer: 
The histamine causes inflammation, skin rash and constriction of the bronchioles (as in 
asthma). 
Question 3. 
How the allergy causing chemical is naturally removed from the body ? 
Answer: 
There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
4. Match the items given under column I with those given under column II. 
column I                                         column II 
 
Answer: 
              column I                                         column II 
 
Question 5. 
Name any three routes of which allergens normally enter in our body. 
Answer: 
1. Skin — Substances that come into contact with the skin, such as latex, are also 
common causes of allergic reactions, known as contact dermatitis or eczema. 
2. Mouth — A wide variety of foods can cause allergic reactions, but 90% of allergic 
responses to foods’are caused by cow’s milk, soy, eggs, wheat, peanuts, tree 
nuts, fish and shellfish. 
3. Nose — Pollen, spores, dust particles and certain chemicals find entry through the 
nose. 
Question 6. 
What are allergens ? Name any three allergens. 
Answer: 
The substances that cause allergies are called allergens. 
1. Dust particles 
2. Nuts 
3. Pollen 
Question 7. 
Name the two tests generally used to diagnose allergy and describe any one of them. 
Answer: 
1. Prick Test—Skin prick test is also known as “puncture testing” or “prick testing” 
due to the series of tiny punctures or pricks made into the patients skin. A small 
plastic or metal device is used to puncture or prick the skin. Sometimes, the 
allergens are injected intradermally into the patients skin, with a needle and 
syringe. Small amounts of suspended allergens or their extracts (e.g., pollen grain, 
insect sting proteins, peanut extracts) are introduced to sites on the skin marked 
with pen or dye. Common areas for testing include the inside of forearm and the 
back. 
2. Blood Testing — A sample of the patient’s blood is sent to a laboratory for 
analysis. Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The 
quantitative allergy blood result can help determine what a patient is allergic to, 
help predict and follow the disease development, estimate the risk of a severe 
reaction, and explain cross-reactivity. 
Question 8. 
Which test is mostly favoured for testing allergy, prick test or blood test ? Why ? 
Answer: 
Blood test is mostly favoured for testing allergy. 
Blood Testing — A sample of the patient’s blood is sent to a laboratory for analysis. 
Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The quantitative 
allergy blood result can help determine what a patient is allergic to, help predict and 
follow the disease development, estimate the risk of a severe reaction, and explain 
cross-reactivity. 
Additional Questions 
Multiple Choice questions : 
1. Put a tick mark ( ?) against the correct alternative in the following statements: 
 
(a) Hay fever and asthma are 
(i) Deficiency diseases 
(ii) Genetic diseases 
(iii) Organic diseases 
(iv) Allergy diseases 
(b) Cataract is a disease of: 
(i)Ears 
(ii) Nose 
(iii) Eyes 
(iv) Throat 
(c) Infectious diseases can be prevented by: 
(i) Medicines 
(ii) Proper food 
(iii) Immunisation 
(iv) Exercise 
(d) Which one of the following is a genetic disease ? 
(i) Scurvy 
(ii) Leukemia 
(iii) Goitre 
(iv) Haemophilia 
(e) Which one of the following is a degenerative disease ? 
(i) Thalassemia 
Page 4


Allergy 
Review Questions 
Question 1. 
Define the term “allergy”. 
Answer: 
Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
Question 2. 
Name the inflammatory chemical released by the basophils causing skin reaction and 
construction of the bronchioles. 
Answer: 
The histamine causes inflammation, skin rash and constriction of the bronchioles (as in 
asthma). 
Question 3. 
How the allergy causing chemical is naturally removed from the body ? 
Answer: 
There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
4. Match the items given under column I with those given under column II. 
column I                                         column II 
 
Answer: 
              column I                                         column II 
 
Question 5. 
Name any three routes of which allergens normally enter in our body. 
Answer: 
1. Skin — Substances that come into contact with the skin, such as latex, are also 
common causes of allergic reactions, known as contact dermatitis or eczema. 
2. Mouth — A wide variety of foods can cause allergic reactions, but 90% of allergic 
responses to foods’are caused by cow’s milk, soy, eggs, wheat, peanuts, tree 
nuts, fish and shellfish. 
3. Nose — Pollen, spores, dust particles and certain chemicals find entry through the 
nose. 
Question 6. 
What are allergens ? Name any three allergens. 
Answer: 
The substances that cause allergies are called allergens. 
1. Dust particles 
2. Nuts 
3. Pollen 
Question 7. 
Name the two tests generally used to diagnose allergy and describe any one of them. 
Answer: 
1. Prick Test—Skin prick test is also known as “puncture testing” or “prick testing” 
due to the series of tiny punctures or pricks made into the patients skin. A small 
plastic or metal device is used to puncture or prick the skin. Sometimes, the 
allergens are injected intradermally into the patients skin, with a needle and 
syringe. Small amounts of suspended allergens or their extracts (e.g., pollen grain, 
insect sting proteins, peanut extracts) are introduced to sites on the skin marked 
with pen or dye. Common areas for testing include the inside of forearm and the 
back. 
2. Blood Testing — A sample of the patient’s blood is sent to a laboratory for 
analysis. Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The 
quantitative allergy blood result can help determine what a patient is allergic to, 
help predict and follow the disease development, estimate the risk of a severe 
reaction, and explain cross-reactivity. 
Question 8. 
Which test is mostly favoured for testing allergy, prick test or blood test ? Why ? 
Answer: 
Blood test is mostly favoured for testing allergy. 
Blood Testing — A sample of the patient’s blood is sent to a laboratory for analysis. 
Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The quantitative 
allergy blood result can help determine what a patient is allergic to, help predict and 
follow the disease development, estimate the risk of a severe reaction, and explain 
cross-reactivity. 
Additional Questions 
Multiple Choice questions : 
1. Put a tick mark ( ?) against the correct alternative in the following statements: 
 
(a) Hay fever and asthma are 
(i) Deficiency diseases 
(ii) Genetic diseases 
(iii) Organic diseases 
(iv) Allergy diseases 
(b) Cataract is a disease of: 
(i)Ears 
(ii) Nose 
(iii) Eyes 
(iv) Throat 
(c) Infectious diseases can be prevented by: 
(i) Medicines 
(ii) Proper food 
(iii) Immunisation 
(iv) Exercise 
(d) Which one of the following is a genetic disease ? 
(i) Scurvy 
(ii) Leukemia 
(iii) Goitre 
(iv) Haemophilia 
(e) Which one of the following is a degenerative disease ? 
(i) Thalassemia 
(ii) Beri-beri 
(iii) Cataract 
(iv) Diabetes 
(f) Pellagra is one disease caused by the deficiency of: 
(i) Vit.B3 
(II) Vit.B1 
(iii) Vit. C 
(iv) Vit. D 
(g) Deficiency of Iodine in one’s food can cause :  
(i) Beri-beri 
(ii) Goitre 
(iii) Scurvy 
(iv) Pellagra 
Short Answer Questions: 
1. (a) What is a non-communicable disease ? 
Ans. The diseases which are caused due to improper functioning of the body organs 
e.g. diabetes, heart attack. They are not caused by germs and not transmitted from one 
to another. 
(b) What is a deficiency disease ? 
Ans. These disease are caused by lack of nutrients, vitamins, minerals as a anaemia, 
goitre. 
(c) What are communicable diseases ? How can they be avoided ? 
Ans. Those disease which spread from one person to another by the entry of 
microorganisms are known as communicable diseases. The disease-causing germs are 
called Pathogens. These disease can be avoided by proper vaccination, healthy food 
and hygenic surroundings. 
(d) Biting nails should be strictly avoided. Give reason. 
Ans. Nail biting may cause many disease as the dirt has many 
bacteria causing diseases. Nails should be cut from time to time to save from diseases. 
(e) Regular exercise and proper rest is a must. Give reason. 
Ans. Regular exercise keeps our body strong and immune to many diseases, rest 
refreshes our body. 
(f) Children eating more of fast food tend to suffer from obesity (overweight). Comment. 
Ans. Fast food like pizza, burger, patty, oily foods etc. have much carbohydrates and 
Page 5


Allergy 
Review Questions 
Question 1. 
Define the term “allergy”. 
Answer: 
Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
Question 2. 
Name the inflammatory chemical released by the basophils causing skin reaction and 
construction of the bronchioles. 
Answer: 
The histamine causes inflammation, skin rash and constriction of the bronchioles (as in 
asthma). 
Question 3. 
How the allergy causing chemical is naturally removed from the body ? 
Answer: 
There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
4. Match the items given under column I with those given under column II. 
column I                                         column II 
 
Answer: 
              column I                                         column II 
 
Question 5. 
Name any three routes of which allergens normally enter in our body. 
Answer: 
1. Skin — Substances that come into contact with the skin, such as latex, are also 
common causes of allergic reactions, known as contact dermatitis or eczema. 
2. Mouth — A wide variety of foods can cause allergic reactions, but 90% of allergic 
responses to foods’are caused by cow’s milk, soy, eggs, wheat, peanuts, tree 
nuts, fish and shellfish. 
3. Nose — Pollen, spores, dust particles and certain chemicals find entry through the 
nose. 
Question 6. 
What are allergens ? Name any three allergens. 
Answer: 
The substances that cause allergies are called allergens. 
1. Dust particles 
2. Nuts 
3. Pollen 
Question 7. 
Name the two tests generally used to diagnose allergy and describe any one of them. 
Answer: 
1. Prick Test—Skin prick test is also known as “puncture testing” or “prick testing” 
due to the series of tiny punctures or pricks made into the patients skin. A small 
plastic or metal device is used to puncture or prick the skin. Sometimes, the 
allergens are injected intradermally into the patients skin, with a needle and 
syringe. Small amounts of suspended allergens or their extracts (e.g., pollen grain, 
insect sting proteins, peanut extracts) are introduced to sites on the skin marked 
with pen or dye. Common areas for testing include the inside of forearm and the 
back. 
2. Blood Testing — A sample of the patient’s blood is sent to a laboratory for 
analysis. Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The 
quantitative allergy blood result can help determine what a patient is allergic to, 
help predict and follow the disease development, estimate the risk of a severe 
reaction, and explain cross-reactivity. 
Question 8. 
Which test is mostly favoured for testing allergy, prick test or blood test ? Why ? 
Answer: 
Blood test is mostly favoured for testing allergy. 
Blood Testing — A sample of the patient’s blood is sent to a laboratory for analysis. 
Multiple allergence can be detected with a single blood sample. 
The test measures the concentration of specific antibodies in the blood. The quantitative 
allergy blood result can help determine what a patient is allergic to, help predict and 
follow the disease development, estimate the risk of a severe reaction, and explain 
cross-reactivity. 
Additional Questions 
Multiple Choice questions : 
1. Put a tick mark ( ?) against the correct alternative in the following statements: 
 
(a) Hay fever and asthma are 
(i) Deficiency diseases 
(ii) Genetic diseases 
(iii) Organic diseases 
(iv) Allergy diseases 
(b) Cataract is a disease of: 
(i)Ears 
(ii) Nose 
(iii) Eyes 
(iv) Throat 
(c) Infectious diseases can be prevented by: 
(i) Medicines 
(ii) Proper food 
(iii) Immunisation 
(iv) Exercise 
(d) Which one of the following is a genetic disease ? 
(i) Scurvy 
(ii) Leukemia 
(iii) Goitre 
(iv) Haemophilia 
(e) Which one of the following is a degenerative disease ? 
(i) Thalassemia 
(ii) Beri-beri 
(iii) Cataract 
(iv) Diabetes 
(f) Pellagra is one disease caused by the deficiency of: 
(i) Vit.B3 
(II) Vit.B1 
(iii) Vit. C 
(iv) Vit. D 
(g) Deficiency of Iodine in one’s food can cause :  
(i) Beri-beri 
(ii) Goitre 
(iii) Scurvy 
(iv) Pellagra 
Short Answer Questions: 
1. (a) What is a non-communicable disease ? 
Ans. The diseases which are caused due to improper functioning of the body organs 
e.g. diabetes, heart attack. They are not caused by germs and not transmitted from one 
to another. 
(b) What is a deficiency disease ? 
Ans. These disease are caused by lack of nutrients, vitamins, minerals as a anaemia, 
goitre. 
(c) What are communicable diseases ? How can they be avoided ? 
Ans. Those disease which spread from one person to another by the entry of 
microorganisms are known as communicable diseases. The disease-causing germs are 
called Pathogens. These disease can be avoided by proper vaccination, healthy food 
and hygenic surroundings. 
(d) Biting nails should be strictly avoided. Give reason. 
Ans. Nail biting may cause many disease as the dirt has many 
bacteria causing diseases. Nails should be cut from time to time to save from diseases. 
(e) Regular exercise and proper rest is a must. Give reason. 
Ans. Regular exercise keeps our body strong and immune to many diseases, rest 
refreshes our body. 
(f) Children eating more of fast food tend to suffer from obesity (overweight). Comment. 
Ans. Fast food like pizza, burger, patty, oily foods etc. have much carbohydrates and 
fats. Children eating these become more and more fat and gain weight soon as they do 
not do much of physical work. 
(g) Define the term “allergy”. 
Ans. Allergies, also known as allergic diseases, are a number of conditions caused by 
hypersensitivity of the immune system to something in the environment that usually 
causes no adverse effects to most people. These diseases include hay fever, 
dermatities, asthma, food allergies, etc. 
(h) Name the inflammatory chemical released by the basophils causing skin reaction 
and construction of the bronchioles. 
Ans. The histamine causes inflammation, skin rash and constriction of the bronchioles 
(as in asthma). 
(i) How the allergy causing chemical is naturally removed from the body ? 
Ans. There are no permanent cure for an allergy. Medication for allergies do give relief. 
Those people prone to allergic reactions should be aware of the allergens that trigger 
these responses in their bodies and avoid them completely, especially food and 
medicines. Allergy shots are helpful to those with seasonal allergies like those caused 
by pollen. 
2. Name the following: 
1. A viral disease caused due to unhealthy sexual contact AIDS. 
2.  A bacterial disease caused due to contaminated water Cholera. 
3. A disease caused due to Plasmodium Malaria. 
4. A disease caused due to the bite of female Culex mosquito Elephantiasis. 
5.  A viral disease caused by the bite of a dog Rabies/ Hydrophobia. 
3. Write short (1-2 sentences) notes on the following: 
Disease, immunisation, allergy, AIDS. 
Answer: 
1. Disease: Disease is a departure from normal health due to structural or functional 
disorder of the body. Disease may be due to deficiency of nutrients or 
malfimctioning of organs or genetic disorders, improper metabolic activity, or 
allergies, or cancer and mental illness as diabetes, haemophilia, leukemia, 
schizophrenia. 
2. Immunisation : It means, we make the body immune to certain diseases by 
introducing respective weakened germs into the body. Thus we develop 
resistance to the concerned disease this process is called immunisation. The 
germs or the material introduced into the body to make it resistant to the 
concerned disease is called vaccine. This produces antibodies in the body of the