Organism

An individual living entity capable of carrying out the processes necessary to maintain life and, where applicable, reproduce.

An organism may consist of a single cell or many cells. Humans, animals, plants, fungi, and bacteria are examples of organisms, although biological classification can become more complex for entities such as viruses that do not meet all conventional definitions of life.

The term is broader than microorganism. Microorganisms are organisms or biological entities that are too small to be seen clearly without magnification, whereas organisms can be microscopic or macroscopic.

COMMONLY CONFUSED WITH

  • Microorganism: an organism or biological entity that is microscopic in size.
  • Infectious agent: an organism or other biological agent capable of causing infection; not every organism is an infectious agent.

SEE ALSO

Clinical & Educational Context

Discussed in Health Articles & Guides

Explore how "Organism" is covered across our evidence-based editorial guides:

2 Articles
Unstraight Lines

Kill Me a Little, Kill It More

From medicines that fight infections to chemicals used to control harmful organisms, the reflection considers the delicate balance between destroying a threat and protecting...
Health in the Wild

Food Packaging: Unexpected Food Safety Risks you need to know

You probably think about what is in your food, but how often do you think about what your food is...