Question

important notes of biology ch -why do we fall ill.

Answer 1

Infectious diseases are caused by pathogens such as bacteria, viruses, fungi and parasites. These pathogens can enter the body through the air we breathe, the food and drink we consume or through openings in the skin, such as cuts. ... Non-infectious diseases aren't caused by pathogens and can't be spread person-to-person.

Or

It may be caused due to the attack of pathogens (virus, bacteria), lack of nutritious diet/balanced diet and lack of public health services. The disease which lasts for only a short period of time is called Acute Disease. Immediate cause: The organisms that enter our body and causes disease is called immediate cause.

Answer 2

You feel ill when your body is not acting up right. If something is wrong with you then you are “ill”