Answer:
Pathogen / Infectious agent is an agent is highly contagious; upon introduction to a population, it spreads rapidly throughout the population. It often causes illness, but not serious illness such as death
Explanation:
Pathogens are the infectious agents which are responsible to cause a diesease or illness to the specific host.
Pathogenic organisms may inlcude bacteria , viruses , fungi , protozoas.
The pathogen cause a disease or illness by following steps :
1) Transmission
2)Adherence to cell surface
3) Invasion , inflammation and intracellular survival.
4) Toxin production.
