LIWA

Disease and Hygiene

ICSE Class 6 · Biology · Chapter 7

What this chapter covers

Key definitions

Health is a state of complete physical, mental and social well-being.

Disease is a condition in which the normal working of the body, or of a part of it, is disturbed.

A symptom is a sign or feeling that tells a person or a doctor that something is wrong in the body.

Hygiene is the set of habits and practices that keep our bodies and our surroundings clean so that we stay healthy.

A communicable disease is a disease that can spread from one person to another.

A non-communicable disease is a disease that does not spread from one person to another.

A germ is a tiny living thing that can enter the body and cause a disease.

Bacteria are very tiny, single-celled living things that are found almost everywhere, in soil, water, air and inside our bodies.

Viruses are germs even smaller than bacteria that can grow and multiply only inside the cells of another living thing.

Protozoa are single-celled living things, larger than bacteria, that live mostly in water or damp places.

A parasite is a living thing that lives on or inside another living thing and takes its food from it, harming it in the process.

The mode of transmission is the way by which the germs of a disease travel from one person to another.

Key points

Questions answered

What is health?
Health is a state of complete physical, mental and social well-being.
Name the two groups into which diseases are sorted, and give one example of each.
Communicable diseases, for example the common cold; non-communicable diseases, for example diabetes.
Name the three groups of germs that cause communicable diseases. Which other living things also cause communicable diseases?
Bacteria, viruses and protozoa. Parasitic worms also cause communicable diseases, but they are not germs.
Match the disease with its germ group: (a) malaria, (b) typhoid, (c) chickenpox.
(a) protozoa; (b) bacteria; (c) virus.
How does a housefly spread disease?
It sits on garbage and dung, and germs stick to its legs. When it then sits on uncovered food, it leaves the germs on the food.
Give two ways to stop diseases that spread through water.
Drink only boiled or filtered water, and store it in a clean, covered container. (Using a ladle to take water out is another way.)
Night blindness cannot be caught from a friend. Why not?
It is a non-communicable deficiency disease caused by too little vitamin A in the diet. It is not caused by germs, so it does not spread.
Into which bin would you put a banana peel, and into which an empty plastic bottle?
The banana peel is wet waste and goes into the green bin. The plastic bottle is dry waste and goes into the blue bin.