NCERT Solutions for Class 9 Science Chapter 13 Why Do We Fall Ill?
Are you looking for simple and accurate NCERT Solutions for Class 9 Science Chapter 13 Why Do We Fall Ill? This article explains key concepts of health, diseases, their causes, prevention, and treatment straightforwardly. Also, we include additional questions and answers so that you can easily prepare for exams and strengthen your Science foundation.
NCERT Textbook Solution for Class 9 – Page No: 178
1. State any two conditions essential for good health.
Answer
Two conditions essential for good health are:
- A balanced diet and sufficient food.
- Clean surroundings and a healthy environment.
2. State any two conditions essential for being free of disease.
Answer
Two conditions essential for being free of disease are:
- Maintaining personal and domestic hygiene.
- Living in a clean and healthy environment.
3. Are the answers to the above questions necessarily the same or different? Why?
Answer
The answers are different because being free of disease only means there is no illness in the body. But good health means a state of complete physical, mental, and social well-being, not just absence of disease. A person may be free from diseases yet not be healthy if their mental or social life is not good.
NCERT Textbook Solution for Class 9 – Page No: 180
1. 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
Three common symptoms that may indicate sickness are:
- Headache
- Cough or cold
- Loose motions
These symptoms show that something may be wrong, but they don’t tell us exactly what the disease is. Even if only one symptom appears, it is better to consult a doctor to find the real cause and get the right treatment.
2. In which of the following case do you think the long-term effects on your health are likely to be most unpleasant?
- If you get jaundice
- If you get lice
- If you get acne.
Answer
Lice and acne are short-term problems that can be treated quickly. But jaundice affects the liver and can harm the body for a long time. So, jaundice has the most unpleasant long-term effects on health.
NCERT Textbook Solution for Class 9 – Page No: 187
1. Why we are normally advised to take bland and nourishing food when we are sick?
Answer:
When we are sick, our body becomes weak. The digestive system also does not work properly. Bland food is easy to digest. Nourishing food gives us nutrients and energy to fight the illness. That is why we are told to eat bland and nourishing food when we are sick.
2. What are the different means by which infectious diseases are spread?
Answer
Infectious diseases spread in many ways:
- Through air: When a sick person coughs, sneezes, or talks, germs can mix with the air and spread diseases like tuberculosis and common cold.
- Through water and food: Drinking dirty water or eating contaminated food can spread diseases like cholera and typhoid.
- Through direct contact: Touching an infected person or using their clothes, bedding, or utensils can spread skin infections and other diseases. Example, fungal infections, skin diseases, scabies etc.
- Through sexual contact: Diseases like AIDS and syphilis spread this way.
- Through body fluids: Infected blood, mother’s milk, or other body fluids can also spread some diseases. Example, AIDS.
- Through vectors: Some animals/insects like mosquitoes carry germs and spread diseases such as malaria and dengue.
- Keeping the school and toilets clean.
- Drinking clean and safe water.
- Washing hands before eating food.
- Covering mouth and nose while coughing or sneezing.
- Avoiding consumption of uncovered food or stale food.
- Staying at home if anyone suffers from infectious diseases.
- Getting vaccinated on time to prevent serious diseases.
4. What is immunisation?
Answer
Immunisation is the process of protecting the body against diseases by giving vaccines. These vaccines help the body to develop immunity so that it can fight against infectious diseases in the future.
5. 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?
Answer
Health centres usually provide vaccines under the Universal Immunisation Programme (UIP). The main vaccines include:
- BCG – against Tuberculosis.
- RVV – against diarrhoea
- PCV -against pneumonia
- DPT – against Diphtheria, Pertussis (Whooping cough), and Tetanus.
- OPV – against Polio
- MR – against Measles and Rubella
- Td -against tetanus and diphtheria
- IPV – against Polio
- Hepatitis B – against Hepatitis B
Among these, diseases such as tuberculosis, diarrhoea, pneumonia and measles are major health problems.
NCERT Textbook Exercises for Class 9 – Page No: 188
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
A doctor, nurse, or health worker avoids getting sick by taking the following precautions:
- They wear masks and gloves while treating patients.
- They wash their hands properly with soap and water or with sanitisers.
- They keep themselves clean and maintain personal hygiene.
- They drink safe water and eat healthy food to keep their immunity strong.
- They avoid direct contact with infected body fluids like blood, urine.
- They use disinfectants to clean instruments and surroundings.
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.
Answer:
The three most common diseases in the neighbourhood are:
- Malaria
- Typhoid
- Cough and Cold
Steps to reduce these diseases:
(a) Keep the surroundings clean.
(b) Provide safe drinking water to all houses.
(c) Organise health camps and vaccination programs to protect people from infections.
(a) that the baby is sick?
(b) what is the sickness?
(a) We can find out that the baby is sick by observing the behavioural changes of the child, such as: constant crying, refusing to eat, frequent mood changes, etc.
(b) The sickness can be determined with the help of symptoms such as fever, vomiting, loose motions, cough, or paleness of the body.
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) A person is most likely to fall sick when she is on a four-day fast after recovering from malaria and is taking care of someone suffering from chickenpox.
This is because her body is weak after malaria and fasting makes her immune system even weaker. As a result, she has a higher chance of getting the chickenpox infection while caring for the patient.
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
A person is more likely to fall sick when their friend is suffering from measles. This is because measles is a highly contagious disease that spreads through air when an infected person coughs or sneezes. So, staying close to a friend with measles increases our chances of getting infected.
Additional Questions and Answers:-
1. Define health.
Answer:- Health is a state of being well enough to function well physically, mentally and socially, not just the absence of disease or illness.
2. Define acute diseases.
Answer:-
Acute diseases are illnesses that develop suddenly and last for a short period of time. They usually get cured quickly, either on their own or with medical treatment. Examples are the common cold, malaria, or typhoid.
3. Define chronic diseases.
Answer:-
Chronic diseases are illnesses that develop slowly and last for a long time, often months or years. They usually affect overall health and can reduce the body’s immunity over time. Examples are Elephantiasis, tuberculosis, diabetes, and high blood pressure
4. What are the causes of diseases?
The causes of diseases can be grouped into different levels:
- Immediate causes: Direct agents like bacteria, viruses, or other microbes that enter the body and make a person sick.
- Second-level causes: Conditions like poor nutrition, weak immunity, or unhealthy lifestyle habits that make the body more vulnerable to diseases.
- Third-level causes: Social, economic, and environmental factors such as poverty, lack of clean drinking water, poor sanitation, or overcrowded living conditions that increase the risk of diseases.
- Genetic factors: Inherited conditions from parents that may lead to certain diseases like some types of cancer or diabetes.
5. Define infectious diseases.
Answer:-
Infectious diseases are illnesses caused by microorganisms like bacteria, viruses, fungi, protozoa, or worms that can spread from one person to another through air, water, food, physical contact, or vectors such as mosquitoes. Examples are malaria, tuberculosis, cholera, and the common cold.
6. Define infectious agents.
Answer:-
Infectious agents are microorganisms such as bacteria, viruses, fungi, protozoa, or worms that enter the body and cause diseases. Each type of infectious agent leads to different illnesses, like viruses causing dengue or bacteria causing tuberculosis.
7. Define Non-infectious diseases
Answer:-
Non-infectious diseases are illnesses not caused by infectious agents. They often result from genetic factors, lifestyle habits, nutritional deficiencies, or environmental conditions. Examples of non-infectious diseases are diabetes, cancer, and high blood pressure.
8. Define communicable diseases.
Answer:-
Communicable diseases are illnesses caused by infectious agents that can spread from one person to another through air, water, food, physical contact, or vectors like mosquitoes. Examples are malaria, tuberculosis, cholera, and the common cold.
9. Define vectors.
Answer:-
Vectors are living organisms that carry and transmit disease-causing microbes from an infected person or animal to a healthy person. Examples of vectors are mosquitoes spreading malaria or dengue and flies spreading diarrheal diseases.
10. Define inflammation.
Answer:-
Inflammation is the body’s protective response to infection or injury, where the affected area becomes red, hot, swollen and painful.
NCERT Solutions for Class 9 Science Chapter 1 Matter In Our Surroundings
NCERT Solutions for Class 9 Science Chapter 2 Is Matter Around Us Pure?
NCERT Solutions for Class 9 Science Chapter 3 Atoms And Molecules
NCERT Solutions for Class 9 Science Chapter 4 Structure Of The Atom
NCERT Solutions for Class 9 Science Chapter 5 The Fundamental Unit Of Life
NCERT Solutions for Class 9 Science Chapter 6 Tissues
NCERT Solutions for Class 9 Science Diversity In Living Organism
NCERT Solutions for Class 9 Science Chapter 8 Motion
NCERT Solutions for Class 9 Science Chapter 9 Force And Laws Of Motion
NCERT Solutions for Class 9 Science Chapter 10 Gravitation
NCERT Solutions for Class 9 Science Chapter 11 Work And Energy
NCERT Solutions for Class 9 Science Chapter 12 Sound
NCERT Solutions for Class 9 Science Chapter 13 Why Do We Fall ill
NCERT Solutions for Class 9 Science Chapter 14 Natural Resources
NCERT Solutions for Class 9 Science Chapter 15 Improvement In Food Resources