Why Do We Fall Ill?| Worksheet Solutions| Class 9

Worksheet solutions for chapter: Why Do We Fall Ill? for class 9 are provided below.

(1) Find out what provisions are made by your local authority for the supply of clean drinking water?

Ans – Provisions made by the local authorities for supply of safe drinking water –

(i) Authorities collect water from the safe sources like river.

(ii) Authorities than treated collected water and distribute treated water for people.

(iii) Water tank also cleaned time to time.


(2) Write the differences between chronic and acute disease.

Ans- Differences between chronic and acute diseases

SN Chronic diseases Acute diseases
1. These diseases last for long – period. These diseases last for short period.
2. These diseases harm health of the patient. These diseases do not harm health of patient.
3. Eg:- Asthma, cancer etc Eg:- Cough, fever etc.


(3) Write down the diseases spread by viruses, bacteria and worm.

Ans- Diseases spread by viruses, bacteria and worm are tabulated below –

SN Microbes Diseases
1. Viruses Common cold, influenza, dengue fever, AIDS
2. Bacteria Typhoid, cholera, tuberculosis and anthrax
3. Worm Intestine infection, elephantiasis


(4) Now a days Corona COVID 19 is spread all over the world. Everyone is seeing towards scientists for it vaccine. Can you explain why?

Ans – Yes, everybody is waiting for vaccine for Corona COVID 19 because our immunisation will be strengthening only after vaccination. Only after vaccination we will be able to fight off against Corona COVID 19 virus.


(5) Why making anti – viral medicines is harder than making anti – bacterial medicines?

Ans- Anti – bacterial medicines are easy to make than the anti – viral medicines because viruses have few biochemical mechanisms of their own. They enter our cells and use our machinery for their life processes.


(6) A person is taking antibiotics in viral fever. What will be your advice to him?

Ans-  I will suggest him not to take antibiotics because it will not be useful in viral fever.

Medicines which are prescribed for one group of bacteria likely to be work for other group of bacteria. But, same medicine will not work for diseases caused by viruses or other group of microbes.


(7) Write down the name of the organ which get affected by the diseases given below –

Jaundice, typhoid, malaria, AIDS

Ans- The organ affected by diseases are given below –

Jaundice affected liver organ.

Typhoid affected gut lining.

Malaria affected to

Aids affected lymph nodes.


(8) What is inflammation?

Ans- The recruitment process in which an active immune system recruits many cells to the affected tissue to kill off the disease – causing microbes is called inflammation.

Eg:- There can be local effects as swelling and pain, general effects as fever.


(9) Write the differences between organ specific and tissue specific diseases.

Ans- Differences between organ specific diseases and tissue specific diseases

SN Organ specific diseases Tissues specific diseases
1. The diseases affected organs like liver, gut lining etc. The diseases affected tissues like lymph nodes etc.
2. Cough, fever, vomiting, pale stool etc are some symptoms. Swelling and pain etc are the symptoms.
3. Eg:- Jaundice, malaria etc. Eg:- AIDS


(10) What are the vector borne diseases and how would you prevent from them?

Ans- The animals which carry infecting agents from a sick person to another potential host are called vectors.

Eg:- mosquitoes, flies etc.

These vectors spread malaria, dengue etc.

Helping Topics

Why Do We Fall Ill?

NCERT Class 9