Information:  - In biology, a species complex is a group of closely related species that are very similar in appearance to the point that the boundaries between them are often unclear. Terms sometimes used synonymously but with more precise meanings are: cryptic species for two or more species hidden under one species name, sibling species for two cryptic species that are each other's closest relative, and species flock for a group of closely related species living in the same habitat. As informal taxonomic ranks, species group, species aggregate, and superspecies are also in use.  - Binomial nomenclature (also called binominal nomenclature or binary nomenclature) is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomial name (which may be shortened to just "binomial"), a binomen or a scientific name; more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs; the second part identifies the species within the genus. For example, humans belong to the genus "Homo" and within this genus to the species "Homo sapiens". The "formal" introduction of this system of naming species is credited to Carl Linnaeus, effectively beginning with his work "Species Plantarum" in 1753. But Gaspard Bauhin, in as early as 1623, had introduced in his book "Pinax theatri botanici" (English, "Illustrated exposition of plants") many names of genera that were later adopted by Linnaeus.  - The International Code of Nomenclature for algae, fungi, and plants (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". It was formerly called the International Code of Botanical Nomenclature (ICBN); the name was changed at the International Botanical Congress in Melbourne in July 2011 as part of the "Melbourne Code" which replaces the "Vienna Code" of 2005. As with previous codes, it took effect as soon as it was ratified by the congress (on Saturday 23 July 2011), but the documentation of the code in its final form was not finished until some time after the congressional meeting. Preliminary wording of some of the articles with the most significant changes has been published in September 2011.  - Botany, also called plant science(s), plant biology or phytology, is the science of plant life and a branch of biology. A botanist or plant scientist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word ("botan") meaning "pasture", "grass", or "fodder"; is in turn derived from ("boskein"), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists study approximately 400,000 species of living organisms of which some 260,000 species are vascular plants and about 248,000 are flowering plants.  - Animals are multicellular, eukaryotic organisms of the kingdom Animalia (also called Metazoa). The animal kingdom emerged as a basal clade within Apoikozoa as a sister of the choanoflagellates. Sponges are the most basal clade of animals. Animals are motile, meaning they can move spontaneously and independently at some point in their lives. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later in their lives. All animals are heterotrophs: they must ingest other organisms or their products for sustenance.  - The plural (abbreviated ), in many languages, is one of the values of the grammatical category of number. Plural of nouns typically denote a quantity other than the default quantity represented by a noun, which is generally one (the form that represents this default quantity is said to be of "singular" number). Most commonly, therefore, plurals are used to denote two or more of something, although they may also denote more than fractional, zero or negative amounts. An example of a plural is the English word "cats", which corresponds to the singular "cat".  - Deoxyribonucleic acid (DNA) is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), they are one of the four major types of macromolecules that are essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix.  - FOSSIL is a standard protocol for allowing serial communication for telecommunications programs under the DOS operating system. FOSSIL is an acronym for "Fido Opus SEAdog Standard Interface Layer". "Fido" refers to FidoBBS, "Opus" refers to Opus-CBCS BBS, and "SEAdog" refers to a Fidonet compatible mailer. The standards document that defines the FOSSIL protocol is maintained by the Fidonet Technical Standards Committee.  - In ecology, a niche is a term with a variety of meanings related to the behavior of a species living under specific environmental conditions. The ecological niche describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts".  - A genus ( genera) is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.  - In biology, offspring are the young born of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee.  - Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution, identification and taxonomy. Modern biology is a vast and eclectic field, composed of many branches and subdisciplines. However, despite the broad scope of biology, there are certain general and unifying concepts within it that govern all study and research, consolidating it into single, coherent field. In general, biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the synthesis and creation of new species. It is also understood today that all the organisms survive by consuming and transforming energy and by regulating their internal environment to maintain a stable and vital condition known as homeostasis.  - In biological classification , rank is the relative level of a group of organisms ( a taxon ) in a taxonomic hierarchy . Examples of taxonomic ranks are species , genus , family , class , kingdom , etc. A given rank subsumes under it less general categories , that is , more specific descriptions of life forms . Above it , each rank is classified within more general categories of organisms and groups of organisms related to each other through inheritance of traits or features from common ancestors . The rank of any species and the description of its genus is basic ; which means that to identify a particular organism , it is usually not necessary to specify ranks other than these first two . Consider a particular species , the red fox Vulpes vulpes : its next rank , the genus Vulpes , comprises all the ' true foxes ' . Their closest relatives are in the immediately higher rank , the family Canidae , which includes dogs , wolves , jackals , all foxes , and other caniforms ; the next higher rank , the order Carnivora , includes feliforms and caniforms ( lions , tigers , bears , hyenas , wolverines , and all those mentioned above ) , plus other carnivorous mammals . As one group of the class Mammalia , all of the above are classified among those with backbones in the Chordata phylum rank , and with them among all the animals in the Animalia kingdom rank . Finally , all of the above will find their earliest relatives somewhere in their domain rank Eukarya . The International Code of Zoological Nomenclature defines rank as : The level , for nomenclatural purposes , of a taxon in a taxonomic hierarchy ( e.g. all families are for nomenclatural purposes at the same rank , which lies between superfamily and subfamily )  - In biology, phylogenetics (Greek: ,  - "phylé", "phylon" = tribe, clan, race +  - "genetikós" = origin, source, birth) is the study of the evolutionary history and relationships among individuals or groups of organisms (e.g. species, or populations). These relationships are discovered through phylogenetic inference methods that evaluate observed heritable traits, such as DNA sequences or morphology under a model of evolution of these traits. The result of these analyses is a phylogeny (also known as a phylogenetic tree)  a diagrammatic hypothesis about the history of the evolutionary relationships of a group of organisms. The tips of a phylogenetic tree can be living organisms or fossils, and represent the "end," or the present, in an evolutionary lineage. Phylogenetic analyses have become central to understanding biodiversity, evolution, ecology, and genomes.  - In biology, a taxon (plural taxa; back-formation from "taxonomy") is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is not uncommon, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.  - Ecdysozoa is a group of protostome animals, including Arthropoda (insects, chelicerata, crustaceans, and myriapods), nematoda, and several smaller phyla. They were first defined by Aguinaldo "et al." in 1997, based mainly on phylogenetic trees constructed using 18S ribosomal RNA genes. A large study in 2008 by Dunn "et al." strongly supported the Ecdysozoa as a clade, that is, a group consisting of a common ancestor and all its descendants.  - In biology, a phylum (plural: phyla) is a taxonomic rank below kingdom and above class. Traditionally, in botany the term division was used instead of "phylum", although from 1993 the International Code of Nomenclature for algae, fungi, and plants accepted the designation "phylum". Depending on definitions, the kingdom Animalia contains approximately 35 phyla, Plantae contains about 12, and Fungi contains around 7. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta.  - Nomenclature codes or codes of nomenclature are the various rulebooks that govern biological taxonomic nomenclature, each in their own broad field of organisms. To an end-user who only deals with names of species, with some awareness that species are assignable to families, it may not be noticeable that there is more than one code, but beyond this basic level these are rather different in the way they work.  - In biological classification, subspecies (abbreviated "subsp." or "ssp."; "plural": "subspecies") is either a taxonomic rank subordinate to species, or a taxonomic unit in that rank. A subspecies cannot be recognized independently: a species will either be recognized as having no subspecies at all or at least two (including any that are extinct).  - Sexual reproduction is a form of reproduction where two morphologically distinct types of specialized reproductive cells called gametes fuse together, involving a female's large ovum (or egg) and a male's smaller sperm. Each gamete contains half the number of chromosomes of normal cells. They are created by a specialized type of cell division, which only occurs in eukaryotic cells, known as meiosis. The two gametes fuse during fertilization to produce DNA replication and the creation of a single-celled zygote which includes genetic material from both gametes. In a process called genetic recombination, genetic material (DNA) joins up so that homologous chromosome sequences are aligned with each other, and this is followed by exchange of genetic information. Two rounds of cell division then produce four daughter cells with half the number of chromosomes from each original parent cell, and the same number of chromosomes as both parents, though self-fertilization can occur. For instance, in human reproduction each human cell contains 46 chromosomes, 23 pairs, except gamete cells, which only contain 23 chromosomes, so the child will have 23 chromosomes from each parent genetically recombined into 23 pairs. Cell division initiates the development of a new individual organism in multicellular organisms, including animals and plants, for the vast majority of whom this is the primary method of reproduction.  - In biology, an organism is any contiguous living system, such as an animal, plant, fungus, archaeon, or bacterium. All known types of organisms are capable of some degree of response to stimuli, reproduction, growth and development and homeostasis. An organism consists of one or more cells; when it has one cell it is known as a unicellular organism; and when it has more than one it is known as a multicellular organism. Most unicellular organisms are of microscopic scale and are thus loosely described as microorganisms. Humans are multicellular organisms composed of many trillions of cells grouped into specialized tissues and organs.  - In biology, a species (abbreviated sp., with the plural form species abbreviated spp.) is the basic unit of biological classification and a taxonomic rank. A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is often problematic. For example, in a species complex, the boundaries between closely related species become unclear or disappear altogether. Other ways of defining species include similarity of DNA, morphology, or ecological niche. The presence of locally adaptive traits may further subdivide species into infraspecific taxa such as subspecies.    Given the paragraphs above, decide what entity has the relation 'part of' with 'taxonomy'.
The answer to this question is:
taxonomic rank