9th Class (CBSE) Science: Why Do We Fall Ill

Question: If someone in the family gets infectious disease, what precautions will you advice to the other family members?

Answer: For an infectious diseased person in the family following precautions should be taken:

1. The surroundings and the house should be clean.
2. The infected person should be kept isolated in a separate room.
3. The clothes and utensils of patient should be sanitised regularly.
4. Separate towels and handkerchief should be used by the patient.
5. Children should not be allowed to visit the infected person.
6. Clean and boiled drinking water should be given to the patient.
7. A balanced and nutritious diet which will provide lot of energy should be given.
8. There should be silence and the patient should be given lot of bed-rest to overcome the infection.

Question: What is a disease? Classify disease based on duration and infection cause.

Answer: Disease can be defined as the state of human health which is not at ease is not comfortable. During disease, the functioning or appearance of one or more systems of the body changes.

Classification:

1. Based on duration:
   Acute diseases: Diseases that last for only short period of time. Example, headache, common cold etc.
   Chronic diseases: Diseases that last for long time is called chronic disease Example, tuberculosis.
2. Based on cause: Disease can be grouped as infectious/communicable disease and non-infectious or non-communicable disease.
   Infectious diseases: These diseases are caused due to microbes and can spread from one person to another.
   Non-infectious diseases: These type of diseases do not spread in the community, but remains internal. Example, cancer, genetic abnormalities.

Question: What are the different ways used for the treatment and prevention of diseases?

Answer: Principles of treatment for diseases are:

1. To reduce the effect of the diseases.
2. To kill the cause of the disease i.e., to kill the microbes like bacteria, fungi, protozoa.

Principles of prevention are:

(I) General ways: It relate to preventing exposure to the microbes. This can be done in following ways:

1. For avoiding air-borne infections—Avoid visiting public place, cover your nose and mouth while sneezing or coughing
2. For water-borne infection: Drink safe, clean and boiled water.
3. For vector-borne diseases: Keep the surroundings clean, keep food and water covered and clean. Do not allow any water to stand as it becomes a breeding ground for mosquitoes.
4. Self immunity: It is self-defence mechanism in our system that can fight off and kill microbes that enter our body.

(II) Specific ways: By giving vaccines, childhood immunisation that is given to children for preventing infections and diseases.

Question: State the mode of transmission for the following diseases: Malaria, AIDS, Jaundice, Typhoid, Cholera, Rabies, Tuberculosis, Diarrhoea, Hepatitis, Influenza.

Answer:

Question: Name all the micro-organisms that causes infectious disease and name few diseases caused by each micro-organism.

Answer: