Pathogens

Definition

Pathogens are microorganisms or agents that cause disease in their host. They can be bacteria, viruses, prions, viroids, or other acellular entities.

5 Must Know Facts For Your Next Test

1. Bacteria and viruses are the most common types of pathogens affecting humans.
2. Pathogens can be transmitted through various means including direct contact, airborne particles, and contaminated food or water.
3. Prions and viroids are unique pathogens that lack nucleic acids and proteins respectively.
4. Antibiotics can treat bacterial infections but are ineffective against viral infections caused by pathogens.
5. The immune system has multiple defenses against pathogens including physical barriers, immune cells, and antibodies.

Review Questions

• What distinguishes a pathogen from a non-pathogenic microorganism?
• How do prions differ from viruses in terms of structure and infection mechanism?
• Why can't antibiotics be used to treat viral infections caused by pathogens?

Related terms

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

Bacterium: A single-celled microorganism that can exist independently or as a parasite.

Prion: An infectious protein particle lacking nucleic acid causing neurodegenerative diseases.