NCERT Class 9 Science Solutions: Chapter 13 Why Do We Fall Ill – Part 2 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 3:

Q. What precautions can you take in your school to reduce the incidence of infectious diseases?


Precautions to reduce incidence of infectious diseases are:

(i) Stay away from the diseased person.

(ii) Cover your mouth or nose while coughing or sneezing to prevent the spread of disease.

(iv) Keep the environment clean to prevent mosquitoes from breeding.

Question 4:

Q. What is immunization?


Immunization is defined as protection of the body from communicable diseases by administration of some agent that mimics the microbe. This suspension of killed microbes that mimics the disease-causing microbes is known as vaccine.

Question 5:

Q. What are the immunization programmes available at the nearest health centre in your locality? which of these diseases are the major health problems in your area?


The immunization programmes available at the nearest health centre are DPT (Diphtheria, Pertusis, and Tetanus) , polio vaccine, hepatitis B, MMR (Measles, Mumps, and Rubella) , jaundice, typhoid, etc. of all these diseases, jaundice and typhoid are major health problems.

Question 1:

Q. How many times did you fall ill in the last one year? What were the illnesses?

(a) Think of one change you could make in your habits in order to avoid any of/most of the above illness.

(b) Think of one change you would wish for in your surroundings in order to avoid any of/most of the above illnesses.


The varies from person to person. Some people fall ill several times in a year while others do not fall ill at all. A person՚s immune system and hygiene-related habits play a major role in determining the person՚s health.

Question 2:

Q. A doctor/nurse/health-worker is exposed to more sick people than others in the community. find out how she/he avoids getting sick herself/himself.


The following precautions must be taken by a doctor/nurse/health-worker:

(i) Wearing a mask when in contact with a diseased person.

(ii) Keeping yourself covered while moving around an infected place.

(iii) Drinking safe water.

(iv) Eating healthy and nutritious food.

(v) Ensuring proper cleanliness and personal hygiene.

Question 3:

Conduct a survey in your neighbourhood to find out what the three most common diseases are. Suggest three steps that could be taken by your local authorities to bring down the incidence of these diseases.


Three most common diseases are:

(i) Tuberculosis

(ii) Typhoid

(iii) Jaundice

Steps to be taken to bring down the incidence of these diseases are:

(i) Proper disposal of sewage.

(ii) Ensuring supply of safe drinking water.

(iii) Providing a clean environment and preventing mosquitoes from breeding.

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