Organisms and groups · Species
Ageratina adenophora
Ageratina adenophora, commonly called crofton weed, is a perennial shrub in the daisy family, Asteraceae.
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EcoGenesis · Encyclopedia
Library of the living world
Organisms, anatomy, processes and learning journeys. Read the explanations and follow their links to data and sources.
A
Organisms and groups · Species
Amanita muscaria
Fly agaric is a mushroom-forming fungus associated with tree roots. Its familiar red cap is only the visible part of this partnership.
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Organisms and groups · Kingdom
Animalia
Animals are multicellular eukaryotes obtaining organic nutrition from other organisms or their remains. Their cells lack cell walls. Most animals have specialized tissues, but sponges show why a familiar arrangement of organs cannot be assumed for every animal. Mobility often changes during life; a larva and an adult can differ substantially.
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Organisms and groups · Species
Arabidopsis thaliana
Arabidopsis thaliana is a small annual flowering plant in the mustard family, Brassicaceae.
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Organisms and groups · Domain
Archaea
Like bacteria, archaea lack a membrane-enclosed nucleus. Their cell envelopes differ, however: characteristic membrane lipids have branched chains with ether linkages, and their walls lack bacterial peptidoglycan. Cells that look similar can therefore differ substantially at the molecular level.
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Organisms and groups · Phylum
Arthropoda
Arthropods combine a segmented body, jointed appendages and an external covering containing chitin. They replace this covering through moulting as they grow. Appendages can support movement, sensing or food handling. Insects, spiders, crustaceans and myriapods illustrate different combinations of these features; their bodies are not all divided into the same regions.
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B
Organisms and groups · Species
Bacillus subtilis
Bacillus subtilis is a Gram-positive bacterium associated with soil and the region around plant roots.
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Organisms and groups · Species
Bacillus subtilis
Bacillus subtilis is a rod-shaped bacterium studied for cell development, protein production and endospore formation.
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Organisms and groups · Domain
Bacteria
Bacterial DNA occupies a region called the nucleoid, without a surrounding nuclear envelope. A cell membrane separates the cell contents from the environment, while ribosomes assemble proteins. Most bacteria have a wall containing peptidoglycan. These features help explain cell organization, but a flagellum or capsule should not be added to every representative.
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C
Organisms and groups · Species
Caenorhabditis elegans
Caenorhabditis elegans is a nematode: a small, free-living roundworm with a transparent body.
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Organisms and groups · Species
Chlamydomonas reinhardtii
Chlamydomonas reinhardtii is a single-celled green alga, not a small animal or a miniature leafy plant.
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D
Organisms and groups · Species
Danio rerio
The zebrafish, Danio rerio, is a small freshwater fish from South Asia, recognizable by dark horizontal stripes along its body.
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Organisms and groups · Species
Drosophila melanogaster
Drosophila melanogaster is a small fly in the family Drosophilidae, familiar both as a laboratory animal and as an inhabitant of fermenting food.
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E
Organisms and groups · Species
Escherichia coli
Escherichia coli occurs in the intestines of people and other animals, but it is also found in water, food and other environmental settings.
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Organisms and groups · Domain
Eukaryota
Eukaryotic cells characteristically have an enclosed nucleus and internal membrane compartments with different functions. This organization lets us study a cell as interacting parts. The parts present depend on the cell type: a diagram containing a chloroplast does not describe every eukaryotic cell.
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F
Organisms and groups · Kingdom
Fungi
Fungi obtain organic compounds from their surroundings and absorb nutrients across cell surfaces. Their cell walls contain chitin and glucans; fungal cells have no chloroplasts of their own. Fungi include single-celled yeasts and forms that grow as threads called hyphae. A mass of hyphae forms a mycelium.
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H
Organisms and groups · Species
Halobacterium salinarum
Halobacterium salinarum is a salt-adapted archaeon, not a bacterium despite the word “bacterium” in its name.
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Organisms and groups · Family
Hominidae
Hominidae includes humans, orangutans, gorillas, chimpanzees and bonobos. Gibbons belong to the broader ape group but not this family. “Hominid” should therefore not be used as a synonym restricted to humans and their fossil relatives.
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Organisms and groups · Genus
Homo
Homo is a genus, while Homo sapiens is the species to which all living humans belong. The genus also includes fossil representatives. For example, early African fossils assigned to Homo erectus have relatively long legs and short arms, proportions associated with movement on the ground. Researchers continue to discuss species boundaries and the interpretation of particular…
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Organisms and groups · Species
Homo sapiens
Homo sapiens is the species to which all living humans belong.
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M
Organisms and groups · Class
Mammalia
Hair and mammary glands that nourish young characterize mammals. Hair can be inconspicuous, as in whales. Their skeletal features include three middle-ear bones. Living mammals include monotremes, marsupials and placentals, so live birth is not a feature of every representative. A platypus lays eggs while still feeding its offspring milk.
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Organisms and groups · Species
Methanocaldococcus jannaschii
Methanocaldococcus jannaschii is an archaeon: it belongs to Archaea, a different domain of cellular life from Bacteria.
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Organisms and groups · Species
Mus musculus
The house mouse, Mus musculus, is a rodent in the family Muridae.
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Organisms and groups · Species
Mycobacterium tuberculosis
Mycobacterium tuberculosis is the bacterium best known for causing tuberculosis, a disease that usually affects the lungs but can also involve other organs.
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P
Organisms and groups · Species
Panthera leo
The lion is a large social cat. Its groups, called prides, defend territories and share the care of young.
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Organisms and groups · Species
Physcomitrium patens
Physcomitrium patens is a moss whose older name, Physcomitrella patens, remains common in research titles.
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Organisms and groups · Species
Picea abies
Norway spruce, Picea abies, is an evergreen conifer in the pine family, Pinaceae.
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Organisms and groups · Species
Picea glauca
White spruce, widely known as Picea glauca, is a North American conifer in the pine family, Pinaceae.
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Organisms and groups · Kingdom
Plantae
Mosses, ferns, conifers and flowering plants illustrate the diversity of land plants. Their life cycles alternate between a spore-producing generation, the sporophyte, and a gamete-producing generation, the gametophyte. The developing embryo receives protection and nourishment from the maternal gametophyte. The size and prominence of these generations differ among groups.
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Organisms and groups · Species
Plasmodium falciparum
Plasmodium falciparum is an apicomplexan parasite that causes malaria in humans.
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Organisms and groups · Order
Primates
Primates include lemurs, tarsiers, monkeys, apes and humans. Grasping adaptations and visual perception of space characterize the group: overlapping visual fields help assess depth. Hand and foot structure, posture and locomotion vary; a human foot is not organized like the grasping foot of a tree-dwelling primate.
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Organisms and groups · Species
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a bacterium found in environmental settings, including soil, water and wet surfaces, as well as in association with plants and animals.
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S
Organisms and groups · Species
Saccharomyces cerevisiae
Saccharomyces cerevisiae is a single-celled fungus best known as baker’s and brewer’s yeast.
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Organisms and groups · Species
Schizosaccharomyces pombe
Schizosaccharomyces pombe is an ascomycete fungus known as fission yeast.
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Organisms and groups · No rank
Severe acute respiratory syndrome coronavirus 2
SARS-CoV-2 is the virus that causes COVID-19, a disease that can range from an infection without symptoms to serious illness.
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T
Organisms and groups · Species
Trypanosoma brucei
Trypanosoma brucei is a eukaryotic parasite classified among the kinetoplastids.
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W
Organisms and groups · Species
Wollemia nobilis
Wollemia nobilis, the Wollemi pine, is a conifer of the Araucariaceae family that came to scientific attention in 1994.
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