51 Biology terminology

An autotroph or primary producer is an organism that produces complex organic compounds using carbon from simple substances such as carbon dioxide, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis). They convert an abiotic source of energy into energy stored in organic compounds, which can be used by other organisms. Autotrophs do not need a living source of carbon or energy and are the producers in a food chain, such as plants on land or algae in water. Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide.

Benthos, also known as benthon, from the Greek benthos meaning "depth of the sea", is the community of organisms that live on, in, or near the seabed, river, lake, or stream bottom, also known as the benthic zone. This community lives in or near marine or freshwater sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.

Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms.

In biology, the canopy is the aboveground portion of a plant croping or crop, formed by the collection of individual plant crowns.

A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste, respectively. Some very simple animals may not have a head, but many bilaterally symmetric forms do, regardless of size.

A clade, also known as a monophyletic group or natural group, is a group of organisms that are monophyletic—that is, composed of a common ancestor and all its lineal descendants - on a phylogenetic tree. Rather than the English term, the equivalent Latin term cladus is often used in taxonomical literature.

Climax species, also called late seral, late-successional, K-selected or equilibrium species, are plant species that can germinate and grow with limited resources, like they need heat exposure or low water availability. They are the species within forest succession that are more adapted to stable and predictable environments, and will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed.

Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.

The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status exist and are in use at international, multi-country, national and local levels as well as for consumer use.

Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals.

The cranial vault is the space in the skull within the neurocranium, occupied by the brain.

Decussation is used in biological contexts to describe a crossing. In Latin anatomical terms, the form decussatio is used, e.g. decussatio pyramidum.

In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a species' range.

Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades, or even millions of years after a mass extinction.

An ecosystem engineer is any animal that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on species richness and landscape-level heterogeneity of an area. As a result, ecosystem engineers are important for maintaining the health and stability of the environment they are living in. Since all organisms impact the environment they live in in one way or another, it has been proposed that the term "ecosystem engineers" be used only for keystone species whose behavior very strongly affects other organisms.

An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local or regional. An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line.

In ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats. Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity.

Experimental factor ontology, also known as EFO, is an open-access ontology of experimental variables particularly those used in molecular biology. The ontology covers variables which include aspects of disease, anatomy, cell type, cell lines, chemical compounds and assay information. EFO is developed and maintained at the EMBL-EBI as a cross-cutting resource for the purposes of curation, querying and data integration in resources such as Ensembl, ChEMBL and Expression Atlas.

Endemism is the state of a species being native to a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is exclusively found in southwestern South Africa and is therefore said to be endemic to that particular part of the world. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range.

Entrainment in the biomusicological sense refers to the synchronization of organisms to an external perceived rhythm such as human music and dance. Humans are the only species for which all individuals experience entrainment, although there are documented examples of entrained nonhuman individuals.

A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale from microscopic to global in extent. It can also be subdivided according to its attributes. Examples include the marine environment, the atmospheric environment and the terrestrial environment. The number of biophysical environments is countless, given that each living organism has its own environment.

A globoid is a spherical crystalline inclusion in a protein body found in seed tissues that contains phytate and other nutrients for plant growth. These are found in several plants, including wheat and the genus Cucurbita. These nutrients are eventually completely depleted during seedling growth. In Cucurbita maxima, globoids form as early as the 3rd day of seedling growth. They are located in conjunction with a larger crystalloid. They are electron–dense and vary widely in size.

A heterotroph is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but not producers. Living organisms that are heterotrophic include all animals and fungi, some bacteria and protists, and many parasitic plants. The term heterotroph arose in microbiology in 1946 as part of a classification of microorganisms based on their type of nutrition. The term is now used in many fields, such as ecology in describing the food chain.

In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents, but can show hybrid vigour, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are.

A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf, are also apex predators.

In biology, a klepton and synklepton is a species that requires input from another biological taxon to complete its reproductive cycle. Specific types of kleptons are zygokleptons, which reproduce by zygogenesis; gynokleptons which reproduce by gynogenesis, and tychokleptons, which reproduce by a combination of both systems. The term is derived from the Greek, kleptein, "to steal".

A landrace is a domesticated, locally adapted, traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolation from other populations of the species. Landraces are generally distinguished from cultivars, and from breeds in the standardized sense, although the term landrace breed is sometimes used as distinguished from the term standardized breed when referring to cattle.

A liana is a long-stemmed, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. Lianas are characteristic of tropical moist deciduous forests, but may be found in temperate rainforests and temperate deciduous forests. There are also temperate lianas, for example the members of the Clematis or Vitis genera. Lianas can form bridges amidst the forest canopy, providing arboreal animals with paths across the forest. These bridges can protect weaker trees from strong winds. Lianas compete with forest trees for sunlight, water and nutrients from the soil. Forests without lianas grow 150% more fruit; trees with lianas have twice the probability of dying.

The earliest known life forms on Earth are putative fossilized microorganisms found in hydrothermal vent precipitates. The earliest time that life forms first appeared on Earth is at least 3.77 billion years ago, possibly as early as 4.28 billion years, or even 4.41 billion years—not long after the oceans formed 4.5 billion years ago, and after the formation of the Earth 4.54 billion years ago. The earliest direct evidence of life on Earth are microfossils of microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks.

Matriphagy is the consumption of the mother by her offspring. The behavior generally takes place within the first few weeks of life and has been documented in some species of insects, nematode worms, pseudoscorpions, and other arachnids as well as in caecilian amphibians.

In microbiology, genetics, cell biology, and molecular biology, competence is the ability of a cell to alter its genetics by taking up extracellular ("naked") DNA from its environment in the process called transformation. Competence may be differentiated between natural competence, a genetically specified ability of bacteria which is thought to occur under natural conditions as well as in the laboratory, and induced or artificial competence, which arises when cells in laboratory cultures are treated to make them transiently permeable to DNA. Competence allows for rapid adaptation and DNA repair of the cell. This article primarily deals with natural competence in bacteria, although information about artificial competence is also provided.

A natural landscape is the original landscape that exists before it is acted upon by human culture. The natural landscape and the cultural landscape are separate parts of the landscape. However, in the 21st century, landscapes that are totally untouched by human activity no longer exist, so that reference is sometimes now made to degrees of naturalness within a landscape.

Oxford Dictionary of Biology is a multiple editions dictionary published by the English Oxford University Press. With more than 5,500 entries, it contains comprehensive information in English on topics relating to biology, biophysics, and biochemistry. The first edition was published in 1985 as A Concise Dictionary of Biology. The seventh edition, A Dictionary of Biology, was published in 2015 and it was edited by Robert Hine and Elizabeth Martin.

In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype. Often there is more than one paratype. Paratypes are usually held in museum research collections.

A perceptual trap is an ecological scenario in which environmental change, typically anthropogenic, leads an organism to avoid an otherwise high-quality habitat. The concept is related to that of an ecological trap, in which environmental change causes preference towards a low-quality habitat.

Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite.

Phototrophs are organisms that carry out photon capture to produce complex organic compounds and acquire energy. They use the energy from light to carry out various cellular metabolic processes. It is a common misconception that phototrophs are obligatorily photosynthetic. Many, but not all, phototrophs often photosynthesize: they anabolically convert carbon dioxide into organic material to be utilized structurally, functionally, or as a source for later catabolic processes. All phototrophs either use electron transport chains or direct proton pumping to establish an electrochemical gradient which is utilized by ATP synthase, to provide the molecular energy currency for the cell. Phototrophs can be either autotrophs or heterotrophs. If their electron and hydrogen donors are inorganic compounds they can be also called lithotrophs, and so, some photoautotrophs are also called photolithoautotrophs. Examples of phototroph organisms are: Rhodobacter capsulatus, Chromatium, Chlorobium etc.

Phototropism is the growth of an organism in response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light have a chemical called auxin that reacts when phototropism occurs. This causes the plant to have elongated cells on the furthest side from the light. Phototropism is one of the many plant tropisms or movements which respond to external stimuli. Growth towards a light source is called positive phototropism, while growth away from light is called negative phototropism (skototropism). Most plant shoots exhibit positive phototropism, and rearrange their chloroplasts in the leaves to maximize photosynthetic energy and promote growth. Some vine shoot tips exhibit negative phototropism, which allows them to grow towards dark, solid objects and climb them. The combination of phototropism and gravitropism allow plants to grow in the correct direction.

Litterfall, plant litter, leaf litter, tree litter, soil litter, or duff, is dead plant material that have fallen to the ground. This detritus or dead organic material and its constituent nutrients are added to the top layer of soil, commonly known as the litter layer or O horizon. Litter is an important factor in ecosystem dynamics, as it is indicative of ecological productivity and may be useful in predicting regional nutrient cycling and soil fertility.

Postglacial vegetation refers to plants that colonize the newly exposed substrate after a glacial retreat. The term "postglacial" typically refers to processes and events that occur after the departure of glacial ice or glacial climates.

In biological classification, the term subspecies refers to one of two or more populations of a species living in different subdivisions of the species' range and varying from one another by morphological characteristics. A single subspecies cannot be recognized independently: a species is either recognized as having no subspecies at all or at least two, including any that are extinct. The term may be abbreviated to subsp. or ssp. The plural is the same as the singular: subspecies.

Syngameon refers to groups of taxa that frequently engage in natural hybridization and lack strong reproductive barriers that prevent interbreeding. Syngameons are more common in plants than animals, with approximately 25% of plant species and 10% of animal species producing natural hybrids. The most well known syngameons include irises of the California Pacific Coast and white oaks of the Eastern United States. Hybridization within a syngameon is typically not equally distributed among species and few species often dominate patterns of hybridization.

The vegetation in Tasmania's alpine environments is predominately woody and shrub-like. One vegetation type is coniferous shrubbery, characterised by the gymnosperm species Microcachrys tetragona, Pherosphaera hookeriana, Podocarpus lawrencei, and Diselma archeri. Distribution of these species is relevant with abiotic factors including edaphic conditions and fire frequency, and increasingly, the threat of climate change towards species survival exists. Conservation and management of coniferous shrubbery are necessary considering that the paleoendemic species, Microcachrys, Pherosphaera and Diselma, have persisted in western Tasmanian environments for millions of years.

In biological classification, taxonomic rank is the relative level of a group of organisms in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc.

A tiller is a stem produced by grass plants, and refers to all shoots that grow after the initial parent shoot grows from a seed. Tillers are segmented, each segment possessing its own two-part leaf. They are involved in vegetative propagation and, in some cases, also seed production.

Tropical vegetation is any vegetation in tropical latitudes. Plant life that occurs in climates that are warm year-round is in general more biologically diverse that in other latitudes. Some tropical areas may receive abundant rain the whole year round, but others have long dry seasons which last several months and may vary in length and intensity with geographic location. These seasonal droughts have great impact on the vegetation, such as in the Madagascar spiny forests. Rainforest vegetation is categorized by five layers. The top layer being the upper tree layer. Here you will find the largest and widest trees in all the forest. These trees tend to have very large canopy's so they can be fully exposed to sunlight. A layer below that is the middle tree layer. Here you will find more compact trees and vegetation. These trees tend to be more skinny as they are trying to gain any sunlight they can. The third layer is the lower tree area. These trees tend to be around five to ten meters high and tightly compacted. The trees found in the third layer are young trees trying to grow into the larger canopy trees. The fourth layer is the shrub layer beneath the tree canopy. This layer is mainly populated by sapling trees, shrubs, and seedlings. The fifth and final layer is the herb layer which is the forest floor. The forest floor is mainly bare except for various plants, mosses, and ferns. The forest floor is much more dense than above because of little sunlight and air movement.

In forestry and ecology, understory, or understorey, also known as underbrush or undergrowth, comprises plant life growing beneath the forest canopy without penetrating it to any great extent, but above the forest floor. Only a small percentage of light penetrates the canopy so understory vegetation is generally shade-tolerant. The understory typically consists of trees stunted through lack of light, other small trees with low light requirements, saplings, shrubs, vines and undergrowth. Small trees such as holly and dogwood are understory specialists.

Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used. There are a number of factors which might cause an individual to become a vagrant—genetic factors and weather conditions are two—but the causes are overall poorly understood. Vagrancy can be a precursor to colonisation if individuals survive.

Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader than the term flora which refers to species composition. Perhaps the closest synonym is plant community, but vegetation can, and often does, refer to a wider range of spatial scales than that term does, including scales as large as the global. Primeval redwood forests, coastal mangrove stands, sphagnum bogs, desert soil crusts, roadside weed patches, wheat fields, cultivated gardens and lawns; all are encompassed by the term vegetation.

A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until spring.

"F0" is defined as the number of equivalent minutes of steam sterilization at temperature 121.1 °C (250 °F) delivered to a container or unit of product calculated using a z-value of 10 °C. The term F-value or "FTref/z" is defined as the equivalent number of minutes to a certain reference temperature (Tref) for a certain control microorganism with an established Z-value.