<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="650" name="life sciences" parent="1019" scope="Branches of science that study living and fossil organisms."/><uf><usefor name="biological sciences"/><usefor name="biology"/></uf><bt><term thcode="2" code="1019" name="sciences" parent="1" scope="Major educational fields, fields of study, and professional groupings within USGS."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><nt><term thcode="2" code="39" name="anatomy and physiology" parent="650" scope="Study of the body structures (anatomy) and life functions and activities (physiology)of plants and animals."/><term thcode="2" code="53" name="aquatic biology" parent="650" scope="The scientific study of organisms living in or near water.  This term is to be used for the science of 'aquatic biology' and for  biological studies in fresh and brackish water. For marine biological studies, use 'marine biology'."/><term thcode="2" code="89" name="biochemistry" parent="650" scope="Study of chemical processes that occur within or are mediated by living organisms."/><term thcode="2" code="127" name="botany" parent="650" scope="The science of plants."/><term thcode="2" code="151" name="cell biology" parent="650" scope="Branch of biology that deals with the study of the formation, structure, and physiology of cells."/><term thcode="2" code="247" name="developmental biology" parent="650" scope="Scientific study of the processes related to the transformation of living organisms from single cells to complex multi-celled individuals."/><term thcode="2" code="311" name="ecology" parent="650" scope="Study of the relations between living plants and animals and their environment."/><term thcode="2" code="320" name="ecotoxicology" parent="650" scope="Scientific study of causes, dispersal, and effects of contaminants on the environment."/><term thcode="2" code="433" name="genetics" parent="650" scope="Branch of biology that deals with heredity or the passing of traits in living organisms from one generation to the next."/><term thcode="2" code="702" name="marine biology" parent="650" scope="Branch of biology concerned with the organisms and habitats of the seas and oceans."/><term thcode="2" code="735" name="microbiology" parent="650" scope="Branch of biology dealing with organisms too small to be seen without the use of a microscope."/><term thcode="2" code="756" name="molecular biology" parent="650" scope="Branch of biology concerned with the study of physiology at the molecular level."/><term thcode="2" code="758" name="morphology (biological)" parent="650" scope="The scientific study of the form, shape, and structure of plants and animals and their fossil remains."/><term thcode="2" code="767" name="mycology" parent="650" scope="Branch of biology concerned with the study of fungi."/><term thcode="2" code="871" name="parasitology" parent="650" scope="Branch of biology concerned with the study of organisms that, living on or in another organism, take nutrition from the host and often harm it."/><term thcode="2" code="876" name="pathology" parent="650" scope="Branch of biology concerned with the study of the causes, progress, symptoms, diagnosis, and effects of diseases."/><term thcode="2" code="1131" name="systematics and taxonomy" parent="650" scope="Study of the identification, naming, and classification of organisms."/><term thcode="2" code="1339" name="zoology" parent="650" scope="Branch of biology that deals with the reproduction, development and growth, anatomy, physiology, and behavior of animals."/></nt><rt><term thcode="2" code="92" name="biodiversity" parent="921" scope="The variety in form, genetics, and ecological roles of organisms within a specific geographic area."/><term thcode="2" code="103" name="biological informatics" parent="585" scope="Development and use of computer, statistical, and other tools in the collection, organization, dissemination, and use of information to solve problems in the life sciences."/><term thcode="2" code="108" name="biological productivity" parent="310" scope="The rate at which primary producers in the ecosystem utilize solar energy to produce food for consumption by other organisms. Do not use this term for productivity of organisms related to studies of the reproduction rates of a species."/><term thcode="2" code="116" name="biota" parent="841" scope="All living organisms in an area."/><term thcode="2" code="238" name="decomposers" parent="841" scope="Organisms, chiefly microorganisms and invertebrates, that feed on dead plant or animal matter breaking it down and recycling the resulting elements and compounds in the environment."/><term thcode="2" code="267" name="disease vectors" parent="533" scope="Organisms, such as insects, that transmit pathogens from one host to another."/><term thcode="2" code="268" name="dispersal (organisms)" parent="310" scope="The dissemination or geographic spread of individuals of a plant or animal population."/><term thcode="2" code="332" name="endangered species" parent="841" scope="Any species that is in danger of extinction throughout all or a significant portion of its range."/><term thcode="2" code="333" name="endemic species" parent="768" scope="Plant and animals species native to and confined to specific geographic areas."/><term thcode="2" code="365" name="extinction and extirpation" parent="310" scope="Extinction is the complete disappearance of a species from the earth.  Extirpation is the complete disappearance (elimination) of a species from a given region, island, or area."/><term thcode="2" code="533" name="health and disease" parent="1174" scope="Normal and abnormal conditions of plant and animal bodies.  Covers both human and non-human health and disease topics. For human health and disease, use the narrower term 'environmental health (human)'."/><term thcode="2" code="602" name="invasive species" parent="797" scope="Plant, animal, or microbe species that is non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm, or harm to human health."/><term thcode="2" code="743" name="migration (organisms)" parent="310" scope="The movement of animals, often periodical, from one area to another due to seasonal changes, availability of food, or climatic conditions."/><term thcode="2" code="768" name="native species" parent="841" scope="Organisms originating in the area where they live."/><term thcode="2" code="777" name="natural resources" parent="1174" scope="Stocks of anything naturally occurring that have a beneficial use for man including economic, nutritional, recreational, aesthetic, and other benefits."/><term thcode="2" code="797" name="nonindigenous species" parent="841" scope="Organisms accidentally or intentionally introduced into areas where they did not previously originate or live."/><term thcode="2" code="841" name="organism groupings (non-taxonomic)" parent="1174" scope="Used for categories of living organisms that are not taxonomic and that include species from more than one taxonomic group."/><term thcode="2" code="843" name="organisms" parent="1174" scope="Living individuals that grow, reproduce, and die."/><term thcode="2" code="861" name="paleontology" parent="291" scope="Study of life in past geologic time based on fossil plants and animals."/><term thcode="2" code="906" name="plant and animal tagging" parent="379" scope="Methods of attaching a tag or marker to an organism as long-term identification for study purposes."/><term thcode="2" code="1020" name="scientific careers" parent="1174" scope="Professions in which people carry out or support scientific research or monitoring."/><term thcode="2" code="1054" name="sexing (plants &amp; animals)" parent="379" scope="Determination of the sex of an individual organism for study purposes, such as wildlife surveys."/></rt></descriptor>