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CBSE Class 8 Science Assertion & Reason
Expert crafted · Instant PDF download · 2026-27

The following Assertion and Reason questions are based on Chapter 3: Health: The Ultimate Treasure from the NCERT Class 8 Science textbook Curiosity. Each question has four options — read both the Assertion (A) and Reason (R) carefully before selecting your answer.

How to attempt Assertion & Reason questions:

(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Assertion & Reason Questions

1
Assertion (A): Health is defined merely as the absence of any disease in the body.

Reason (R): A healthy person can perform various tasks more efficiently and cope well in different situations.
Answer: (d)
A is false, but R is true. According to the WHO, health is not merely the absence of disease, but a state of complete physical, mental, and social well-being.
2
Assertion (A): Fever and high blood pressure are considered signs of an illness rather than symptoms.

Reason (R): A sign is something that can be seen or measured, whereas a symptom is what we feel, like pain or tiredness.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Since fever and blood pressure can be measured by a doctor, they are classified as signs.
3
Assertion (A): Diseases like diabetes, cancer, and asthma can easily spread from an infected person to a healthy person.

Reason (R): Non-communicable diseases are usually linked to lifestyle, diet, and environmental factors.
Answer: (d)
A is false, but R is true. Diabetes, cancer, and asthma are non-communicable diseases, meaning they do not spread from person to person.
4
Assertion (A): Houseflies and mosquitoes are often referred to as vectors in the context of human health.

Reason (R): They carry and spread disease-causing pathogens from one person to another.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Insects that transmit infectious pathogens between humans (or from animals to humans) are termed vectors.
5
Assertion (A): Controlling mosquito breeding in and around our homes helps prevent the spread of dengue and malaria.

Reason (R): Dengue fever and malaria are transmitted through the bite of infected mosquito vectors.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because these diseases rely on mosquitoes to spread, eliminating their breeding grounds effectively stops transmission.
6
Assertion (A): Diseases like scurvy, anaemia, and goitre are communicable diseases.

Reason (R): Deficiency diseases are caused by a lack of specific nutrients in the diet.
Answer: (d)
A is false, but R is true. Scurvy, anaemia, and goitre are deficiency diseases. Because they are caused by nutritional lack and not pathogens, they are non-communicable.
7
Assertion (A): A vaccine provides acquired immunity by training the immune system to recognise and attack harmful germs.

Reason (R): Vaccines usually contain weakened, dead, or harmless parts of a pathogen.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. By introducing harmless pathogen material, the vaccine safely trains the immune system to fight future infections.
8
Assertion (A): Edward Jenner discovered the first vaccine, which was used to protect people from smallpox.

Reason (R): Jenner observed that milkmaids who had cowpox did not catch smallpox.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Jenner's observation of cowpox resistance led him to experiment with cowpox sap, resulting in the invention of the smallpox vaccine.
9
Assertion (A): Antibiotics are highly effective in curing viral infections like the common cold and flu.

Reason (R): Antibiotics target specific parts of bacterial cells that are different from human or animal cells.
Answer: (d)
A is false, but R is true. Antibiotics only kill or inhibit bacteria. Because they target bacterial cell structures, they are completely ineffective against viruses.
10
Assertion (A): We should take antibiotics only when prescribed by a doctor and complete the full course.

Reason (R): Indiscriminate and unnecessary use of antibiotics can lead to the development of antibiotic-resistant bacteria.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Overusing antibiotics causes bacteria to adapt and survive the treatment, leading to dangerous antibiotic resistance.
11
Assertion (A): Regular handwashing and avoiding sharing of personal items are preventive measures against the common cold.

Reason (R): The common cold is a non-communicable disease.
Answer: (c)
A is true, but R is false. The common cold is a highly communicable disease caused by a virus, which is exactly why handwashing and not sharing items prevents its spread.
12
Assertion (A): Tuberculosis (TB) primarily affects the lungs and spreads through the air from an infected person.

Reason (R): Tuberculosis is a communicable disease caused by a virus.
Answer: (c)
A is true, but R is false. While TB does affect the lungs and spread through the air, it is caused by bacteria, not a virus.
13
Assertion (A): Drinking boiled water and consuming properly cooked food helps prevent Cholera and Typhoid.

Reason (R): Cholera and Typhoid are communicable diseases that spread through contaminated water and food.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Since the pathogens for these diseases enter the body via contaminated food and water, boiling and proper cooking destroy them.
14
Assertion (A): All communicable diseases are caused by pathogens.

Reason (R): Pathogens are disease-causing organisms like bacteria, viruses, fungi, or protozoa.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Communicable diseases rely entirely on these specific disease-causing microorganisms (pathogens) to spread from person to person.
15
Assertion (A): In recent years, non-communicable diseases like diabetes and heart disease have become more common in India.

Reason (R): This rise is due to changes in lifestyle, such as eating more processed food and getting less exercise.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. The shift towards unhealthy diets, reduced physical activity, and increased screen time has directly contributed to the surge in NCDs.
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❓ Frequently Asked Questions
What is covered in CBSE Class 8 Science Chapter 3 Health: The Ultimate Treasure?
This chapter covers all key topics from Health: The Ultimate Treasure as per CBSE 2026-27 syllabus.
Is this Assertion & Reason useful for CBSE board exams?
Yes, designed for CBSE Class 8 board exam preparation covering the complete syllabus.
Are these CBSE Class 8 Science Assertion & Reason updated for 2026-27?
Yes, all content at eBookPublisher is updated as per the latest 2026-27 CBSE syllabus.
How many chapters are in CBSE Class 8 Science?
All chapters of CBSE Class 8 Science are covered at eBookPublisher with free Assertion & Reason for each chapter.
Can I study Health: The Ultimate Treasure online for free?
Yes, complete Assertion & Reason for Health: The Ultimate Treasure is available free at eBookPublisher. Study online directly — no download needed.
Where can I get a complete Assertion & Reason book for CBSE Class 8 Science?
You can purchase the complete expert-crafted Assertion & Reason book for CBSE Class 8 Science at eBookPublisher.in. Instant PDF download after payment.