Concise Selina Solutions for Class 8 Biology Chapter 8 Disease and First Aid


Disease is caused by the deficiency of nutrients or improper functioning of the body or genetic disorder. It is defined as the departure from actual health to illness, due to structural or functional disorder of the body. Example: Cancer, brain tumour, heart attack etc.

Disease: the disorder of the body. The organisms that cause diseases are called a pathogen. E.g., bacteria, virus, fungi, protozoans.

Types of diseases:

Communicable diseases – spread from one person to other

Non-communicable diseases -do not spread from one person to other.

Causes of diseases – Micro-organisms, malfunctioning of body organs, deficiency of nutrients, genetic factors, polluted environment, drug addictions

Disease get transmitted -through the air, water, physical contact and vectors—prevention of diseases – balanced diet, immunisation, personal hygiene.

First aid is the first and immediate assistance given to any person suffering from either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery. First Aid training gives you the confidence to step in to help when an emergency occurs. Responding straight away, the action you take could save a life or prevent a person who has a permanent disability. Identifying hazards is another benefit of knowing First Aid.