Selina Class 7 Biology Solutions Chapter-7 Allergy
Introduction to Allergy
Allergy is an important health-related topic included in the ICSE biology syllabus for Class 7. Selina Class 7 Biology Solutions help students understand the causes, symptoms, prevention, and treatment of allergies in a simple and effective manner. Students studying with Selina Solutions for ICSE board can prepare textbook exercises, important definitions, and symptom-based questions related to allergies and immunity.
Find the Exercise-wise PDF of Selina Class 7 Biology Solutions chapter-7 Allergy.
What is an Allergy?
An allergy is a condition in which the body reacts abnormally to certain substances known as allergens. These substances are usually harmless for most people but may cause reactions in sensitive individuals.
Common Allergens
The chapter explains different substances that may trigger allergies:
- Dust
- Pollen
- Smoke
- Certain foods
- Medicines
- Insect bites
- Animal fur
How Allergies Occur
Allergies occur when the immune system becomes overly sensitive to allergens. The body releases chemicals that produce symptoms such as sneezing, itching, swelling, and skin irritation.
Types of Allergies
Respiratory Allergy
Respiratory allergies affect the nose and lungs. Dust, smoke, and pollen are common causes.
Skin Allergy
Skin allergies may result in rashes, redness, and itching due to chemicals, cosmetics, or insect bites.
Food Allergy
Certain foods such as milk, seafood, nuts, or eggs may trigger allergic reactions in some people.
Symptoms of Allergy
The chapter discusses several symptoms of allergies:
- Sneezing
- Watery eyes
- Coughing
- Skin rashes
- Itching
- Swelling
- Breathing difficulty
Students learn to identify these symptoms for better health awareness.
Prevention of Allergies
Preventive measures are important for controlling allergies. The chapter emphasizes:
- Maintaining cleanliness
- Avoiding dust accumulation
- Following personal hygiene
- Staying away from known allergens
Treatment of Allergies
Doctors may recommend medicines like antihistamines to control allergic reactions. Avoiding allergens is also an effective preventive measure.
Importance of This Chapter
This chapter helps students understand basic health care and environmental cleanliness. It also increases awareness about common allergic conditions experienced in daily life.
Benefits of Selina Solutions for Chapter 7
Selina solutions provide clear answers for textbook exercises, definitions, and short notes. Students can revise important terms like allergens, antihistamines, and immunity more effectively through regular practice.
FAQs on Selina Class 7 Biology Solutions Chapter-7 Allergy
Allergens are substances that cause allergic reactions in sensitive individuals. Examples include dust, pollen, smoke, certain foods, and medicines. These substances trigger abnormal responses from the immune system, leading to symptoms like sneezing, itching, or swelling.
Common symptoms include sneezing, watery eyes, coughing, skin irritation, itching, and breathing problems. Different people may experience different symptoms depending on the type of allergen and body sensitivity.
Selina solutions explain allergy-related concepts in simple language and provide accurate textbook answers. Students can practice definitions, symptoms, prevention methods, and important questions effectively. Regular revision helps improve understanding and examination performance.