1. What’s the solution ?

You are very hungry, but the food has been left uncovered.

Ans: Heating kills all the disease-causing germs present in the food. So if food is left uncovered, one should heat the food and then eat it when hungry. Eating warm food is always good for your health.

2. Use your brain power !

Which method of preventing the breeding of mosquitoes will you recommend for your surroundings – not allowing water to stagnate or spraying insecticides on the water ? Why ?

Ans: In order to prevent the breeding of mosquitoes, don’t let the water stagnate, as mosquitoes breed only where water stagnates. They lay eggs in dirty water and wet garbage to start their life cycle.

However, if there are nullahs or gutters in the surrounding area, spraying insecticide on the water will be recommended to kill the mosquito larvae growing in it. Therefore, both methods need to be used sometimes.

3. Answer the following questions.

(a) What is an infectious disease?

Ans: Diseases that spread from one person to another are called infectious diseases.

(b) What are the mediums of the spread of diseases ?

Ans: Air, water, food and insects are the mediums through which diseases spread.

(c) What happens when there is an epidemic of a disease?

Ans: When there is an epidemic of a disease, many people in one area get the same infectious disease at the same time.

(d) What is vaccination?

Ans: When a person is given a vaccine against a specific disease, he develops resistance to that disease. This process of giving vaccines is called vaccination.

(e) Make a list of the vaccinations that are given to a newborn baby.

Ans: Vaccinations given to a newborn baby are:

(i) BCG Vaccine – Against Tuberculosis.

(ii) Hepa B vaccine – Jaundice caused by Hepatitis B.

(iii) Oral Polio – Against Polio.

(iv) Triple vaccine – Against Diphteria, whooping cough and tetanus.

4. True or false ?

(a) Intestinal diseases spread through air.

Ans: False

(b) Some diseases are caused by the anger of the gods.

Ans: False

5. Classify the diseases given below as diseases that spread through food, through water and through air.

Malaria, typhoid, cholera, tuberculosis, Jaundice, gastro, diarrhoea, diphtheria.

Ans:

Through food – typhoid, jaundice, gastro, diarrhoea.

Through water – cholera.

Through air – tuberculosis, diphtheria.

6. Give reasons.

(a) When there is an epidemic of cholera, we should drink boiled water.

Ans: Cholera is an intestinal disease in which germs are present in the faeces of infected people, which, when mixed with water, make them contaminated. Therefore, to prevent the transmission of this disease, we should drink boiled water, as boiling kills all the infectious germs present in it.

(b) We should not allow puddles of water to stand in our surroundings.

Ans: We should not allow water to stagnate in and around our house to prevent mosquitoes from breeding in the stagnated water. Once they hatch, they can cause various diseases like malaria, dengue fever, etc. Stagnant water can produce a pretty bad smell, which can cause a lot of discomfort.