CBSE Questions for Class 9 Biology Why Do We Fall Ill Quiz 2 - MCQExams.com

• An airborne disease is any disease that is caused by pathogens and transmitted through the air via respiratory droplets.
• The airborne transmission is by small particles or droplets that contain these infectious agents or pathogens. 
• Tuberculosis, Pneumonia and the common cold are infectious diseases and are airborne.

• Health is a state of complete physical, mental and social well-being and not merely the absence of diseases. One can be considered to be in a state of positive health when his surrounding conditions provide him a healthy environment. 
• Unhygienic conditions like sewage, domestic water, garbage, toxic substances, and harmful gases pollute the surrounding environment which may cause several diseases and psyche disorders that ultimately deteriorates the health of a person.

• Prevention is better than treatment because it prevents the discomfort and cost of becoming sick or experiencing a similar type of infection. 
• It also often takes less effort to prevent something than to treat it. 
• Sometimes treatment has certain side effects.

• According to WHO: “Health is a complete state of physical, mental and social well-being, and not merely the absence of disease or infirmity.” 

Correct Option: D

Explanation:

• According to WHO, “health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”
• Health may be improved by promoting healthy behaviours like regular physical activity and getting enough sleep, as well as limiting or avoiding unhealthy activities like smoking or excessive stress.

Hence, health is a state of mental and physical well-being of the body.

• A chronic condition is a condition where the metabolism of the body is severely disturbed and it lasts for a longer duration. 
• They maybe present from birth. 
• Common chronic diseases include arthritis, asthma, cancer, COPD, diabetes, and viral diseases such as hepatitis C and HIV/AIDS.

• The acute diseases develop suddenly and last for a short time for few days or week. Examples of acute diseases are viral fever, pneumonia and common cold.
• The chronic disease develop slowly and require a longer term treatment. Examples of chronic diseases are tuberculosis, cancer, and diabetes.
• So, the correct answer is option D.

• A healthy person can be disease-free, but a disease-free person may not necessarily be a healthy person. 
• Health is determined by all three factors - physical, mental, and social well-being.
• Health defines as a state of complete physical, mental and social well-being and not merely the absence of disease.