NCERT Solutions for Class 9 Science Chapter 13 Why do we fall ill

Here we have given NCERT Solutions for Class 9 Science Chapter 13 Why Do We Fall III.

Board	CBSE
Textbook	NCERT
Class	Class 9
Subject	Science
Chapter	Chapter 13
Chapter Name	Why Do We Fall III
Number of Questions Solved	16
Category	NCERT Solutions

NCERT Solutions for Class 9 Science Chapter 13 Why Do We Fall III

INTEXT Questions

Question 1.
State any two conditions essential for good health.
Solution:

• Better sanitation or clean surroundings
• Good economic conditions.

Question 2.
State any two conditions essential for being free of disease.
Solution:

• Living in hygienic environment.
• Getting vaccinated against common infectious diseases.

Question 3.
Are the answers to the above questions (2 and 3) necessarily the same or different? Why?
Solution:
Answers to above questions are interconnected but different. It is so because being disease free does not mean one is healthy.

Question 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?
Solution:
The three reasons of feeling sick and to go to see a doctor are as follows :

• having body temperature,
• having diarrhoea (loose motions), and
• having cough/cold.

If only one symptom persists, then also one should go to a doctor. The doctor will diagnose on the basis of the symptoms. Doctor will also get laboratory tests done to pin point the disease further.

Question 5.
In which of the following case do you think the long-term effects on your health are likely to be most unpleasant ?
(a) If you get jaundice,
(b) If you get lice,
(c) If you get acne. Why?
Solution:
In case of attack of jaundice, there would be long-term effects on my body. It is so because jaundice is a disease in which liver is affected. It takes more time to recover from this disease. On the other hand, lice can be removed easily with short treatment and so is the acne. Both these do not produce long¬term effects on the body.

Question 6.
Why are we normally advised to take bland and nourishing food when we are sick?
Solution:
Bland food is soft and can be easily digested and assimilated in body. Nourishing food increases resistance for disease and is essential for repair and growth of body tissue.

Question 7.
What are the different means by which infectious diseases are spread ?
Solution:
Infectious diseases are generally spread through air, water, sexual contact, vectors, physical contact with affected person and through articles of use of affected person.

Question 8.
What precautions can you take in your school to reduce the incidence of infectious diseases?
Solution:
Following precautions can be taken in the school to reduce the incidence of infectious diseases :

• Providing clean drinking water,
• Educating students about causes of infectious diseases, .
• Vacccination of students against common infectious diseases from time to time,
• Proper sanitation or clean environment in school and its surroundings to eradicate vectors of infectious diseases, and
• By not allowing the affected students to attend the classes till they recover from infectious diseases.

Question 9.
What is immunisation ?
Solution:
Immunisation is a technique in which people are given particular vaccine so that they develop temporary/permanent immunity against a particular infectious disease. In other words, immunisation is a specific way of preventing infectious diseases.

Question 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 ?
Solution:
Immunisation programmes are as follows :

• BCG vaccination against tuberculosis
• Polio drops against polio disease
• Vaccination against chicken pox
• Vaccination against hepatitis
• DPT vaccination against diphtheria, pertussis (Whooping cough) and tetanus.
• Immunisation against measles.

Major health problems are :

• Hepatitis
• Chicken-pox
• Tuberculosis
• Polio.

NCERT Exercises

Question 1.
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 illnesses.
(b) Think of one change you would wish for in your surroundings in order to avoid any of/ most of the above illnesses.
Solution:
I suffered last year from cough and cold (twice) and malaria (once).
(a) Change in habits : Wear suitable clothes in order to give protection to the body during changing season and against mosquito bite.
(b) Change in surroundings :

• Improve the sanitary conditions in the surroundings,
• Do not allow water to collect near the houses, because it provides the breeding ground for mosquitoes.

Question 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.
Solution:
A doctor/nurse/health worker is exposed to more sick people in the community. He/she avoids getting sick by:

• keeping place of work sterilised by using phenyl etc.
• keeping equipments, that are regularly in use, sterilised.
• washing hands with soap thoroughly after serious examination of patients.
• getting themselves vaccinated against various diseases.

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.
Solution:
After conducting a survey in my neighbourhood, I found out that the three most common diseases in my area are diarrhoea, malaria and typhoid. Three steps that could be taken by local authorities to bring down the incidences of these diseases are :

• proper disposal of garbage and regular cleaning of roads and streets
• regular cleaning of drains and spraying of insecticides
• provision of clean drinking water.

Question 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?
(b) what is the sickness?
Solution:
(a) Symptoms that help us to find that baby is sick, are :

• Continuous crying and restlessness of the child
• Improper intake of food and body temperature.

(b) Kind of sickness can be known by certain organ-specific and tissue-specific symptoms for e.g., yellowness of skin and eyes indicate the jaundice and hepatitis.

Question 5.
Under which o’, 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 caking 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. Why?
Solution:
A person is most likely to fall sick in (c) condition because malaria attack has caused large scale destruction of her blood cells so she is weak and anaemic. Then she is on a four- day fast and not getting proper and sufficient food which further decreases the functioning of her immune system and lastly chickenpox is a communicable and contagious disease.

Question 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. Why?
Solution:
I will be most likely to fall sick when my friend is suffering from measles and I come in contact with him because measles is contagious disease and also spreads by droplet infection.

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