1. What are non- communicable diseases?

Disease which does not spread from one person to another person is called a non communicable disease.

2. Explain epidemic.

When a large number of people get the same disease over the same period of time, it is said to be an epidemic.

Example: Malaria

3. Write two benefits of exercise.

(a)  Exercise strengthen bones and muscles.

(b)  It increases the efficiency of the heart and improves blood circulation.

4. What is a disease?

Disease is a state of unhealthy condition of the body in which one or more parts are affected and the body does not function normally.

5. Name two diseases caused by vitamin A and vitamin D.

Vitamin A causes night blindness. Vitamin D cause rickets where bones become brittle and thin.

6. Name two disease caused by the deficiency of minerals.

Iodine deficiency causes goitre. Iron deficiency causes anaemia.

7. What is goitre?

Goitre is the swelling of thyroid gland in the neck region.

8. What is allergy?

Allergy is a state when some people are exposed to dust, they sneeze. Different people are allergic to different things, for example to medicines, food, chemicals etc.

9. Name one disease that spreads through water.

Cholera is spread by drinking contaminated water.

10. Write a short note on how diseases are spread through food.

Germs grow fast on garbage and dirt. Flies sit on these and carry the germs that stick to their legs. When food is left uncovered, these flies sit on it, the germs are left on the food and contaminate. Anybody eating contaminated food is likely to fall ill .

11. Give three ways to stop disease from spreading.

      • Always drink pure and clean water .
      •Always keep the food covered .Do not eat spoiled food.
      •If a person is suffering from a communicable disease, keep him isolated .

12. What are vaccines ? Name a vaccine.

Vaccines are medicines that can prevent a disease from occurring. It enables our body to fight the disease causing germs when they enter the body .
Example:  Hepatitis B can be prevented by vaccination.

13. What are the effects of vitamin D deficiency and how can it be prevented ?

Vitamin D deficiency cause rickets. It is a state where bones become thin and brittle .The diet should include fish liver oil, egg, milk and milk products. Mild exposure to sunlight also increases the vitamin D .Sun is a rich source of vitamin D.

14. Name two diseases caused by bacteria, protozoa, fungi and virus.

Bacteria :-     Typhoid , Meningitis
Protozoa :-    Malaria, Dysentery
Fungi :-          Nail infections, Ringworm
Virus :-          Influenza ,Swine flu

15. Name two diseases spread through air.

Diseases like common cold , Diphtheria etc spread through air.