organisms

Life forms overall

Organisms are living things—entities that grow, reproduce, respond to stimuli, and maintain internal processes.

The term covers everything from bacteria to blue whales: The pond contains thousands of microscopic organisms.

In biology, organism distinguishes individual living units from populations, species, or ecosystems.

Figuratively, any complex system with interdependent parts may be called an organism: the social organism.

microscopic

bacteria

Nucleus-free single-celled organisms

  • archaeaThird domain of life
  • protozoaSingle-celled eukaryotic organisms
  • virusesSubmicroscopic infectious particles

plankton · algae · amoeba · paramecium · euglena · diatoms · microbes · pathogens · microbiota · yeast

diversity

biodiversity

Range of life forms

endemic · exotic · endangered · threatened · extinction · conservation · habitats · genetic diversity · populations · adaptation

macroscopic

animals

Multicellular mobile organisms

  • plantsPhotosynthesizing rooted organisms
  • mammalsHair-bearing, milk-producing animals
  • birdsEgg-laying flying vertebrates

reptiles · amphibians · fish · insects · trees · shrubs · vertebrates · invertebrates · megafauna · wildlife

biology

species

Finest taxonomic rank

physiology · genetics · morphology · cellular · metabolism · reproduction · heredity · phylogeny · homology · biochemistry

evolution

natural selection

Differential reproductive success

genetic drift · common descent · phylogeny · ancestry · fossils · paleontology · Darwinism · survival of the fittest · reproductive success · cladistics

ecology

ecosystem

Interconnected organisms and surroundings

community · biosphere · symbiosis · competition · predation · food web · keystone species · carrying capacity · succession · biotic

lifecycle

birth

Coming into the world

death · aging · maturation · senescence · metamorphosis · gestation · regeneration · homeostasis · juvenile · adult

Categories
Opposites
living vs. non-living matter

organismsminerals

Inorganic natural solids

rocks · stones · crystals · metals · corpses

natural vs. artificial entities

organismsmachines

Devices that perform tasks

robots · constructs · artifacts · automatons · mechanisms

Phrases
Family

organism, microorganism

Familiarity
Top 50,000
Profile
Known to kids · Used worldwide · Timeless · Concrete · Everyday, not technical · Rated G