Zoology - Human Health and Diseases Question with Solution | TestHub

A wide range of organisms belonging to bacteria, viruses, fungi, protozoans, helminths, etc., can cause diseases in man. Such disease-causing organisms are called pathogens. All parasites are therefore pathogens as they cause harm to the host by living in (or on) them. The pathogens can enter our body by various means, multiply and interfere with normal vital activities, resulting in morphological and functional damage. Pathogens have to adapt to life within the environment of the host.