The Class 9 is an important year in a student’s life and Science is one of the subjects that require dedication, hard work, and practice. It’s a subject where you can score well if you are well-versed with the concepts, remember the important formulas and solving methods, and have done an ample amount of practice. Worry not! Home Revise is here to make your Class 9 journey even easier. It’s essential for students to have the right study material and notes to prepare for their board examinations, and through Home Revise, you can cover all the fundamental topics in the subject and the complete NCERT Class 9 Science Book syllabus.
1. State any two conditions essential for good health.
Solution:
Two conditions essential for good health are given below:
1. State of physical, mental and social well-being.
2. Better surroundings or environment.
2. State any two conditions essential for being free of disease.
Solution:
Two conditions essential for being free of disease are listed below:
1. Personal and domestic hygiene.
2. Clean environment and surroundings.
3. Are the answers to the above questions necessarily the same or different? Why?
Solution:
The answers to the above questions can be different because a person may be free of disease but not be good mentally, socially and economically.
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?
Solution:
1. Headache
2. Cough
3. Loose motions
These indicate that there may be a disease, but they don’t indicate what the disease is. Hence, one would still visit the doctor for treatment and to know the cause of the above symptoms.
Even if a single symptom is present, one needs to consult the doctor to get proper treatment.
2. In which of the following case do you think the long-term effects on your health are likely to be most unpleasant?
Solution:
Lice and acne will not cause any long-term effects on the human body. However, the effects of jaundice will be long-term and most unpleasant.
Jaundice is a chronic disease that impacts the whole body and takes a longer time to be cured completely.
1. Why are we normally advised to take bland and nourishing food when we are sick?
Solution:
During sickness, the body becomes weak, and the digestive system does not work properly. So easily digested food needs to be taken during this period as well as food rich in nutrients is advised to take. The immunity of the body decreases during disease or infection. Hence, bland and nourishing food is given for speedy recovery.
2. What are the different means by which infectious diseases are spread?
Solution:
Infectious diseases are generally spread through the following modes – Water, air, vectors such as mosquitoes, sexual contact, physical contact with the affected, or by using the affected person’s clothes, bedding, utensils, etc.
3. What precautions can you take in your school to reduce the incidence of infectious diseases?
Solution:
Some of the precautions that we can take in our school to reduce the incidence of infectious diseases are as follows:
1. Drinking clean and hygienic water.
2. Preventing the accumulation of water in surroundings.
3. Keeping the toilet neat and clean.
4. Avoiding consumption of uncovered food and other eatables.
5. Taking a bath daily
6. Have a balanced diet.
7. Provide a clean environment which prevents the breeding of mosquitoes. This prevents the spread of vector-borne diseases.
4. What is immunisation?
Solution:
The method to boost our immune system with the help of vaccines that help the body to fight against infectious diseases is called immunisation.
5. What are the immunisation programs available at the nearest health centre in your locality? Which of these diseases are the major health problems in your area?
Solution:
The following immunisation programme is available at the nearest health centre in our locality:
1. Immunisation for infants – DPT, BCG, polio, measles and MMR.
2. For children – Typhoid, TT, DT, smallpox and TAB.
3. For pregnant women— TT and hepatitis B.
The diseases like typhoid, polio, and measles are the major health problems in our locality.
1. How many times did you fall ill in the last 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 fell ill twice in the last year. I suffered from diarrhoea first and then dengue fever.
(a) The changes made by me in my habits after suffering from these diseases are as given below:
(i) I will always drink purified and clean water and wash my hands before eating any food item.
(ii) I will live in a clean environment where disease-spreading vectors will not multiply.
An example of multiplying vectors is mosquitoes.
(b) One change I would wish for in our surroundings in order to have a healthy society is to make pure drinking water available for the people. Consuming impure water is the root cause of many infectious diseases.
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:
Some important precautions that need to be taken by the doctor/nurse/health worker while treating people who are sicker than others in the community are listed below:
(a) Do not forget to wear a mask when in contact with a diseased person.
(b) Drinking purified water.
(c) Not neglecting cleanliness and personal hygiene.
(d) Keeping themselves covered appropriately when moving in an infected region.
(e) Eating nutritious food and maintaining a healthy diet.
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:
The following three are the most common diseases in any neighbourhood:
Cold and cough, loose motions, and malaria.
Some of the preventive measures that can be taken are as follows:
(a). By drinking fresh, uncontaminated, and clean water.
(b). By maintaining hygienic sanitary conditions.
(c). By educating people about various preventive measures with the help of posters and pamphlets.
4. A baby is not able to tell her caretakers that she is sick. What would help us to find out
(a) that the baby is sick?
(b) what is the sickness?
Solution:
(a). It can be found out by observing the behavioural changes of the child, such as: