CBSE Class 9 Science Why do we Fall ill Assignment Set A

1.”Health” is a state of being well enough to function well physically, mentally, and socially.

2.”Disease”( disturbed ease) means being uncomfortable. One or more systems of the body will change, give rise to “Symptoms” (Cough, loose motions, pus formation, headache, fever, breathlessness, vomiting, fits, unconsciousness, inflammation , swelling and general effects - a Doctor look for the basis of symptoms). Diseases are basically two types- Acute Disease & Chronic Disease

3. Acute Disease: The disease which lasts for only a short period of time is called Acute Disease Ex. Common Cold.

4.Chronic Disease: The disease which lasts for long period of time is called Chronic Disease Ex. Tuberculosis.

5. Causes of Diseases : Most of the diseases have many causes, rather than one single cause, like unclean water, nourishment, genetic differences, genetic abnormalities e.g. Based on the causes diseases are of two types: Non-Infectious Diseases and Infectious Diseases.

6. Non-Infectious Diseases: Not caused by infectious agents, mostly internal and noninfectious cause. Ex. Cancer

7. Infectious Diseases: Caused by infectious agents.

a)The infectious diseases spread by agents are called as Communicable Diseases.

9. Principles of Treatment:

1. Antibiotics: many bacteria make a cell wall to protect themselves, the antibiotic (Penicillin) blocks the bacterial process that builds cell wall and blocks the biochemical pathways. Antibiotics do not work against viral infections. Antiviral medicine is harder than making Antibacterial medicine because Virus has only few biochemical mechanisms of their own. Other medicines bring down fever, reduce pain or loose motions. We can take bed rest to conserve energy.

10 Principles of Prevention : Following three limitation are normally confronted while treating an infectious disease:

• Once someone has disease, their body functions are damaged and may never recover completely.
• Treatment will take time, which means that someone suffering from a disease is likely to be bedridden for some time even if we can give proper treatment.
• The person suffering from an infectious disease can serve as the source from where the infection may spread to other people.

General ways of preventing infectious disease :

• Air-borne – We can prevent exposure by providing living condition that are not overcrowded.
• Water-borne – prevent by providing safe drinking water. This is done by treating the water to kill any microbial contamination.
• Vector-borne – We can provide clean environment, which would not allow mosquito breeding.

11. Immunity: Even in cells there is repair mechanism called” Immunity”. Immune cells manage to kill off the infectious agents. Smallpox disease is eliminated by developing memory cells for particular infection by mimics the microbes, called” Vaccine”. The basis of Immunization- if you had smallpox once, there was no chance of suffering from it again.
Proper nutrition is essential to maintain body immunity. There are vaccines against tetanus, diphtheria, whooping cough, measles, polio and many other diseases.

12. Prevention of disease is better than cure. Hygiene is the basic key to maintain good health.

Important Question and Answer :

Question. Name any two Symptoms of diseases………………………. (Cough& loose motions)
Question. Write short notes on Immunity(Even in cells there is repair mechanism called” Immunity”. Immune cells manage to kill off the infectious agents.)
Question. The disease which last for only a short period of time is called……………….( Acute Disease)
Question. Mention the causal organism for Sleeping sickness ………… (Trypanosoma)
Question.Cholera is a waterborne disease, mention TRUE/ FALSE ……….. (TRUE)
Question. Define Health……. (It is astate of being well enough to function well physically, mentally, and socially)
Question. State whether Tuberculosis is aChronic Disease or Acute Disease…… (Chronic Disease)
Question. Explain with an example the term Vaccine. ( Smallpox disease is eliminated by developing memory cells for particular infection by mimics the microbes, called” Vaccine”).
Question. Antibiotics do not work against viral infections, mention TRUE/ FALSE ……….. (TRUE)

Why do we Fall ill

Q 1 Write the name of the organism that causes kala-azar.

Q 2 What is a disease?

Q 3 Write one example of both infectious and non-infectious disease?

Q 4 Which type of disease is most dangerous for the health?

Q 5 What happens if the body is suffering from a disease?

Q 6 What are the social aspects that are necessary for individual health?

Q 7 Which organism is responsible for causing malaria?

Q 8 What are vectors?

Q 9 Define health.

Q 10 Name four diseases for which vaccines are available.

Q 11 What do you understand by the term ‗sleeping sickness‘? Give it‘s symptoms.

Q 12 How does community health depend on personal health?

Q 13 How does AIDS virus spread?

Q 14 Why the making of antiviral medicines is harder than antibacterial?

Q 15 What is the difference between acute and chronic diseases?

QUESTIONS

Q 1 Which organism is responsible for causing malaria?

Q 2 What are the social aspects that are necessary for individual health?

Q 3 What happens if the body is suffering from a disease?

Q 4 Which type of disease is more dangerous for health?

Q 5 Write one example of both infectious and non-infectious disease?

Q 6 What is a disease?

Q 7 Write the name of the organism that causes kala-azar.

Q 8 Define health.

Q 9 Name two diseases transmitted through contaminated food and water.

Q 10 Name 2 bacterial diseases in man.

Q 11 Name 2 viral diseases in man. 

Q 12 Which organism causes malignant malaria?

Q 13 What is meant by droplet infection?

Q 14 What is cell?

Q 15 What is the difference between good health and bad health?

Q 16 What is the difference between acute and chronic diseases?

Exam Questions NCERT Class 9 Science Chapter 13 Why do we fall ill

Question. What causes Japanese encephalitis? How it can be prevented?
Ans :(i) Japanese encephalitis is caused by virus which enters into human body through mosquito bite.
(ii) By keeping the surrounding clean and taking proper measures against mosquito bite, it can be prevented.

Question. Write the expanded form of AIDS.
Ans : Acquired Immuno Deficiency Syndrome.

Question. Why is immune system essential for our health?
Ans : The immune system of our body is a type of defence mechanism to fight against pathogenic microbes. It has cells that are specialized to kill infecting microbes and keep our body healthy.

Question. Give difference between Congenital Diseases and Acquired Diseases.
Ans : Congenital :
(i) These occur since from birth.
(ii) Inherited from the parents to the offspring. Acquired : (i) It occurs during the lifetime of the person and not from the birth. (ii) It does not get inherited. It occurs due to pathogens or due to deficiency of nutrients, hormonal imbalance or due to degeneration of the tissues.

Question. Name any two groups of microorganisms from which antibiotics could be extracted.
Ans : Bacteria and fungi.

Question. A child is suffering from fever but the doctor cannot immediately pinpoint the ailment on the basis of this one symptom. Explain, why? Also mention another two such general symptoms.
Ans : Only one symptom cannot tell the name of disease. For example : a headache may just be due to an examination stress or due to meningitis or one of a dozen different diseases. Similarly, fever may be due to different reasons.

Question. Which animal plays the role of vector for malaria?
Ans : Female Anopheles mosquito.

Question. Why is AIDS a fatal disease?
Ans : In AIDS, immune system of the body is highly weakened and body suffers from severe infections which lead to death of the individual. Hence, it is a fatal disease.

Question. Which is the most common type of Plague?
Ans : Bubonic Plague is the most common type of Plague.

Question. What are non-communicable diseases? Give examples.
Ans : Those diseases which cannot be spread from person to person, e.g., Diabetes, Cancer, etc.