Looking for accurate SEBA Class 9 Science Chapter 13 (Why Do We Fall Ill) textual solutions for the 2026–27 academic year? Access step-by-step textbook exercise answers, detailed explanations on acute vs. chronic diseases, infectious agents, modes of transmission, immunization, and disease prevention principles designed to help you score top marks in your annual exams.
Blue question
1. State any two conditions essential for good health.
Answer:
Two conditions essential for good health are having a balanced diet and living in a clean and hygienic environment.
2. State any two conditions essential for being free of disease.
Answer:
Two conditions essential for being free of disease are having no infection in the body and maintaining personal and community hygiene.
3. Are the answers to the above questions necessarily the same or different? Why?
Answer:
They are different. Good health means complete physical, mental, and social well-being, while being disease-free means only the absence of illness. A person may be disease-free but still unhealthy due to stress, poor diet, or an unclean environment.
4. List any three reasons why you would think that you are sick and ought to see a doctor. If only one of these symptoms were present, would you still go to the doctor? Why or why not?
Answer:
Reasons for feeling sick:
- High fever
- Continuous headache
- Severe vomiting or diarrhoea
If only one symptom is present, I may or may not go to the doctor. If the symptom is mild, I may wait and observe. If it is severe or continues for long, I should go to the doctor to prevent complications.
SEBA Class 9 Science Chapter 13 Solutions
5. In which of the following cases do you think the long-term effects on your health are likely to be most unpleasant: jaundice, lice, or acne? Why?
Answer:
Jaundice has the most unpleasant long-term effects because it affects the liver, a major organ of the body. Lice and acne are minor and do not usually cause serious health problems.
6.Why are we normally advised to take bland and nourishing food when we are sick?
Answer:
Because bland and nourishing food is easy to digest, gives energy, and helps the body recover faster without irritating the stomach.
7. What are the different means by which infectious diseases are spread?
Answer:
Infectious diseases spread through:
- Air – cough, sneezing
- Water – contaminated drinking water
- Food – spoiled or unhygienic food
- Vectors – mosquitoes, houseflies
- Direct contact – touching an infected person
- Indirect contact – sharing utensils, towels, etc.
8. What precautions can you take in your school to reduce the incidence of infectious diseases?
Answer:
Keep classrooms clean and dust-free.
Wash hands regularly.
Do not share water bottles or handkerchiefs.
Ensure clean drinking water.
Keep distance from sick classmates.
9. What is immunisation?
Answer:
Immunisation is the process of giving vaccines to protect the body from infectious diseases by developing immunity.
Class 9 Science Chapter 13 Question Answer SEBA 2026-27
10. What are the immunisation programmes available at the nearest health centre in your locality? Which of these diseases are the major health problems in your area?
Answer:
Common immunisation programmes include vaccines for:
Tuberculosis (BCG)
Polio
Measles
DPT (Diphtheria, Pertussis, Tetanus)
Hepatitis B
Typhoid
COVID-19 (if available)
Textbook question
1. How many times have 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 illnesses.
Answer: I can wash my hands regularly and avoid eating outside junk food.
(b) Think of one change you would wish for in your surroundings in order to avoid any of/most of the above illnesses.
Answer: I would wish for proper garbage disposal and clean, unpolluted surroundings to prevent the breeding of germs and mosquitoes.
2. 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.
Answer: They avoid getting sick by:
- Wearing masks, gloves, and protective clothing
- Washing hands or using sanitiser frequently
- Taking vaccinations
- Maintaining good hygiene and proper disposal of waste
- Keeping their immune system strong with healthy food and rest
Why Do We Fall Ill Class 9 SEBA Textual Exercise Solutions
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.
Cough and cold
Dengue
Diarrhoea
Answer: Steps local authorities can take:
- Ensure clean drinking water supply
- Regular fogging and mosquito control
- Proper garbage collection and drainage cleaning
4. A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find out
(a) that the baby is sick?
Answer: We can observe:
- Continuous crying
- Fever
- Refusal to eat or drink
- Unusual sleepiness or restlessness
(b) what is the sickness?
Answer: Caretakers can find out through:
Checking temperature
Noticing symptoms like cough, rashes, vomiting
Taking the baby to a doctor for examination and tests
SEBA Class 9 Science Chapter 13 Notes
5. Under which of the following conditions is a person most likely to fall sick?
(a) when she is recovering from malaria.
(b) when she has recovered from malaria and is taking care of someone suffering from chicken-pox.
(c) when she is on a four-day fast after recovering from malaria and is taking care of someone suffering from chicken-pox.
Answer:
(c)
Because after malaria the body is already weak, and fasting reduces strength further. Also, taking care of someone with chicken-pox increases exposure to infection. So the chances of falling sick are highest.
6. Under which of the following conditions are you most likely to fall sick?
(a) when you are taking examinations.
(b) when you have travelled by bus and train for two days.
(c) when your friend is suffering from measles.
Answer:
(c)
Because measles is a highly infectious disease and spreads easily through air.
Conditions (a) and (b) may cause tiredness, but they do not expose you to a contagious disease.
Class 9 Science Chapter 13 Question Answer
🔬 Updated Solutions Notice: This page features complete, step-by-step SEBA Class 9 Science Chapter 13 (Why Do We Fall Ill) Textual Exercise Solutions updated for the 2026–27 academic session. All distinctions between infectious and non-infectious diseases, health definitions, vector-borne illnesses, and vaccination concepts strictly follow the latest revised Assam Board (SEBA) textbook.
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