Answer:
The germ theory of disease was given by Louis Pasteur. The theory states that pathogen or microbe is the cause of any disease. This pathogen can be isolated from the infected organism and must be grown in pure culture.
This pure culture must cause disease when it is injected into a healthy organism. Then the same bacteria must be isolated from the second host.
This theory is helpful in knowing the cause of disease and finding the prevention and cure of the disease.
