{"doi":"10.1002/9780470015902.a0029349","title":"Protozoa","abstract":"<jats:title>Abstract</jats:title><jats:sec><jats:label/><jats:p>Protozoa may be considered as (mostly) microscopic, essentially single‐celled, eukaryotes that ingest other organisms or their products (i.e. as heterotrophic protists). Protozoa are no longer recognised as a taxonomic group because they do not constitute a monophylum and can be found in all main eukaryotic lineages, informally called supergroups. They play important roles in the ecology of aquatic habitats and soils, for example, by controlling bacterial populations and releasing nutrients for use by other organisms. As parasites, protozoa have very profound effects on humans, both directly and through their effects on domesticated animals. Some protozoa have shells or skeletal structures that can fossilise and certain groups, particularly the foraminifera, are used in biostratigraphy and in locating oil deposits.</jats:p></jats:sec><jats:sec><jats:title>Key Concepts</jats:title><jats:p><jats:list list-type=\"bullet\"><jats:list-item><jats:p>Protozoa are single‐celled eukaryotes (protists) that obtain their food by eating other organisms or their products.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa are not a taxonomic group but rather a diverse assemblage of heterotrophic, distantly related lineages, with representatives in all eukaryote supergroups.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa help to understand evolution of multicellularity since animals and fungi evolved from them.</jats:p></jats:list-item><jats:list-item><jats:p>Study of protozoa provides an inside into the biology of the last eukaryotic common ancestor and the evolution of eukaryotic cell.</jats:p></jats:list-item><jats:list-item><jats:p>Algae (photosynthetic protists) evolved from protozoa several times independently by acquiring plastid from cyanobacteria (primary plastid) or other plastid‐bearing protists (secondary and tertiary plastids).</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa diversified to a tremendous number of morphological forms; two elementary body plans are flagellate and amoeba. The amoeboid body plan was invented several times during the evolution of eukaryotes.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa are found in almost every habitat where there is a sufficient amount of water and may survive adverse environmental conditions by the production of cysts or spores.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa play key roles in nutrient cycling and soil fertility and are the main predators of bacteria in many environments.</jats:p></jats:list-item><jats:list-item><jats:p>A wide range of human and animal diseases are caused by protozoa.</jats:p></jats:list-item><jats:list-item><jats:p>Fossil protozoa are used to help locate oil deposits and to reconstruct past climate changes.</jats:p></jats:list-item></jats:list></jats:p></jats:sec>","journal":"Encyclopedia of Life Sciences","year":2021,"id":672371,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1438151,"name":"Tomáš Pánek","orcid":"0000-0002-1738-8430","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Protozoa","abstract":"<jats:title>Abstract</jats:title><jats:sec><jats:label/><jats:p>Protozoa may be considered as (mostly) microscopic, essentially single‐celled, eukaryotes that ingest other organisms or their products (i.e. as heterotrophic protists). Protozoa are no longer recognised as a taxonomic group because they do not constitute a monophylum and can be found in all main eukaryotic lineages, informally called supergroups. They play important roles in the ecology of aquatic habitats and soils, for example, by controlling bacterial populations and releasing nutrients for use by other organisms. As parasites, protozoa have very profound effects on humans, both directly and through their effects on domesticated animals. Some protozoa have shells or skeletal structures that can fossilise and certain groups, particularly the foraminifera, are used in biostratigraphy and in locating oil deposits.</jats:p></jats:sec><jats:sec><jats:title>Key Concepts</jats:title><jats:p><jats:list list-type=\"bullet\"><jats:list-item><jats:p>Protozoa are single‐celled eukaryotes (protists) that obtain their food by eating other organisms or their products.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa are not a taxonomic group but rather a diverse assemblage of heterotrophic, distantly related lineages, with representatives in all eukaryote supergroups.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa help to understand evolution of multicellularity since animals and fungi evolved from them.</jats:p></jats:list-item><jats:list-item><jats:p>Study of protozoa provides an inside into the biology of the last eukaryotic common ancestor and the evolution of eukaryotic cell.</jats:p></jats:list-item><jats:list-item><jats:p>Algae (photosynthetic protists) evolved from protozoa several times independently by acquiring plastid from cyanobacteria (primary plastid) or other plastid‐bearing protists (secondary and tertiary plastids).</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa diversified to a tremendous number of morphological forms; two elementary body plans are flagellate and amoeba. The amoeboid body plan was invented several times during the evolution of eukaryotes.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa are found in almost every habitat where there is a sufficient amount of water and may survive adverse environmental conditions by the production of cysts or spores.</jats:p></jats:list-item><jats:list-item><jats:p>Protozoa play key roles in nutrient cycling and soil fertility and are the main predators of bacteria in many environments.</jats:p></jats:list-item><jats:list-item><jats:p>A wide range of human and animal diseases are caused by protozoa.</jats:p></jats:list-item><jats:list-item><jats:p>Fossil protozoa are used to help locate oil deposits and to reconstruct past climate changes.</jats:p></jats:list-item></jats:list></jats:p></jats:sec>","is_dataset_classified":null,"base_score":0.0,"endowment":0.0,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"19965766","pmcid":null,"openalex_id":"https://openalex.org/W4233676141","authors":[],"funders":[],"total_grants":0,"fwci":null,"citation_percentile":null,"influential_citations":0,"citation_trend":[],"oa_status":"closed","license":"http://doi.wiley.com/10.1002/tdm_license_1.1","oa_locations":[{"url":"https://onlinelibrary.wiley.com/doi/pdf/10.1002/9780470015902.a0029349","host_type":"publisher"},{"url":"https://onlinelibrary.wiley.com/doi/full-xml/10.1002/9780470015902.a0029349","host_type":"publisher"},{"url":"https://doi.org/10.1002/9780470015902.a0029349","host_type":"journal"}],"fields_of_study":["Protist diversity and phylogeny","Geology and Paleoclimatology Research","Methane Hydrates and Related Phenomena"],"mesh_terms":[],"keywords":["Protozoa","Biology","Protist","Phylum","Algae","Plastid","Acanthamoeba","Flagellate","Eukaryote","Multicellular organism","Phylogenetics","Amoeba (genus)","Ecology","Zoology","Botany","Bacteria","Microbiology","Paleontology","Genome","Genetics"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-16T08:50:56.010439Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}