Pathogen

Definition

A pathogen is a microorganism that causes disease in its host. Pathogens can be bacteria, viruses, fungi, or other microorganisms.

5 Must Know Facts For Your Next Test

1. Pathogens can be classified into different types such as bacterial, viral, fungal, and protozoan.
2. Not all bacteria are pathogens; some are beneficial to humans and the environment.
3. Pathogens have various transmission methods including air, water, direct contact, and vectors like insects.
4. The human body has multiple defense mechanisms against pathogens including physical barriers like skin and immune responses.
5. Antibiotics can treat bacterial infections but are ineffective against viral infections.

Review Questions

• What are the main types of pathogens?
• How do pathogens typically spread from one host to another?
• Why can't antibiotics be used to treat viral infections?

Related terms

Bacterium: A single-celled microorganism that can be either beneficial or harmful to humans.

Virus: A microscopic infectious agent that requires a living host cell to replicate.

Immune Response: The body's defense mechanism against pathogens involving various cells and proteins.