ecology, study of the relationships between organisms and their environment. Some of the most pressing problems in human affairs—expanding populations, food scarcities, environmental pollution including global warming, extinctions of plant and animal species, and all the attendant sociological and

bioelectricity: …nearly all cases, however, a bioelectric current consists of a flow of ions (i.e., electrically charged atoms or molecules), whereas the electric current used for lighting, communication, or power is a movement of electrons. If two solutions with different concentrations of an ion are separated by a membrane that blocks…

bioelectric organ, system of tissues specialized for the production and use of electrical power in a living organism. Well developed in a wide variety of fishes, both marine and freshwater, indicating an early evolutionary development, bioelectric organs probably represent a specialization of a

bioelectricity: Bioelectric potentials are generated by a variety of biological processes and generally range in strength from one to a few hundred millivolts. In the electric eel, however, currents of one ampere at 600 to 1,000 volts are generated. A brief treatment of bioelectricity follows. For…

human nutrition: Body mass, body fat, and body water: …is measured using skinfold calipers; bioelectrical impedance, in which resistance to a low-intensity electrical current is used to estimate body fat; and near infrared interactance, in which an infrared light aimed at the biceps is used to assess fat and protein interaction. Direct measurement of the body’s various compartments can…

bioelectricity, electric potentials and currents produced by or occurring within living organisms. Bioelectric potentials are generated by a variety of biological processes and generally range in strength from one to a few hundred millivolts. In the electric eel, however, currents of one ampere at

bioengineering, the application of engineering knowledge to the fields of medicine and biology. The bioengineer must be well grounded in biology and have engineering knowledge that is broad, drawing upon electrical, chemical, mechanical, and other engineering disciplines. The bioengineer may work

environmental engineering, the development of processes and infrastructure for the supply of water, the disposal of waste, and the control of pollution of all kinds. These endeavours protect public health by preventing disease transmission, and they preserve the quality of the environment by

bioethics, branch of applied ethics that studies the philosophical, social, and legal issues arising in medicine and the life sciences. It is chiefly concerned with human life and well-being, though it sometimes also treats ethical questions relating to the nonhuman biological environment. (Such

sedimentary facies: …more correctly, paleontological) attributes—the fossils—define biofacies. Both are the direct result of the depositional history of the basin. By ascribing modes of origin to different facies (i.e., interpreting the lithofacies or biofacies) one can visualize a genetic system of facies. It is also common to speak of alluvial facies, bar…

feedback, in biology, a response within a system (molecule, cell, organism, or population) that influences the continued activity or productivity of that system. In essence, it is the control of a biological reaction by the end products of that reaction. Similar usage prevails in mathematics,

biofeedback, information supplied instantaneously about an individual’s own physiological processes. Data concerning a person’s cardiovascular activity (blood pressure and heart rate), temperature, brain waves, or muscle tension is monitored electronically and returned, or “fed back,” to that

biofeedback, information supplied instantaneously about an individual’s own physiological processes. Data concerning a person’s cardiovascular activity (blood pressure and heart rate), temperature, brain waves, or muscle tension is monitored electronically and returned, or “fed back,” to that

biofilm, aggregate of bacteria held together by a mucuslike matrix of carbohydrate that adheres to a surface. Biofilms can form on the surfaces of liquids, solids, and living tissues, such as those of animals and plants. Organisms in biofilms often display substantially different properties from

vitamin: Bioflavinoids: The bioflavinoids once were thought to prevent scurvy and were designated as vitamin Pc, but additional evidence refuted this claim.

biodegradability: Stages and rates of biodegradation: BiofragmentationDuring biofragmentation, saprotrophic organisms excrete enzymes that progressively reduce the molecular weight of the material. This often involves breaking down polymers into smaller dimers and monomers. In preparation for assimilation, organic chemicals are further broken down either by aerobic

biofuel, any fuel that is derived from biomass—that is, plant or algae material or animal waste. Since such feedstock material can be replenished readily, biofuel is considered to be a source of renewable energy, unlike fossil fuels such as petroleum, coal, and natural gas. Biofuel is commonly

biogas, naturally occurring gas that is generated by the breakdown of organic matter by anaerobic bacteria and is used in energy production. Biogas differs from natural gas in that it is a renewable energy source produced biologically through anaerobic digestion rather than a fossil fuel produced

cell: Contribution of other sciences: …to establish the principle of biogenesis—namely, that organisms arise only by the reproduction of other organisms. Fundamental ideas regarding the metabolic attributes of cells—that is, their ability to transform simple nutritional substances into cell substance and utilizable energy—came from microbiology. Pasteur perhaps overplayed the relation between catalysis and the living…

Ryuzo Yanagimachi: In 2000 Yanagimachi founded the Institute for Biogenesis Research at the University of Hawaii. The institute, devoted to studying embryogenesis, stem cell development, and transgenesis technology, was funded by the National Institutes of Health as well as by private donations. Yanagimachi directed the institute until 2004 and continued teaching until…

biogenetic law, postulation, by Ernst Haeckel in 1866, that ontogeny recapitulates phylogeny—i.e., the development of the animal embryo and young traces the evolutionary development of the species. The theory was influential and much-popularized earlier but has been of little significance in

sedimentary facies: …transported to the depositional site; biogenic, representing accumulations of whole or fragmented shells and other hard parts of organisms; or chemical, representing inorganic precipitation of material from solution. As conditions change with time, so different depositional sites may change their shapes and characteristics. Each facies thus has a three-dimensional configuration…

biogenic gas, any gas critical for and produced by living organisms. Biogenic gases in the atmosphere play a role in the dynamics of Earth’s planetary radiation budget, the thermodynamics of the planet’s moist atmosphere, and, indirectly, the mechanics of the fluid flows that are Earth’s planetary

climate: Biogenic ice nuclei: As water vapour condenses onto condensation nuclei, the droplets grow in size. Growth proceeds at relative humidity as low as 70 percent, but the rate of growth is very slow. Growth by condensation is most rapid where the air is slightly supersaturated…

biogenic landform, any topographic feature that can be attributed to the activity of organisms. Such features are diverse in both kind and scale. Organisms contribute to the genesis of most topography involving rock weathering, although the role they play is usually auxiliary, as demonstrated by

biogenic ooze, any pelagic sediment that contains more than 30 percent skeletal material. These sediments can be made up of either carbonate (or calcareous) ooze or siliceous ooze. The skeletal material in carbonate oozes is calcium carbonate usually in the form of the mineral calcite but sometimes

biogenic ooze, any pelagic sediment that contains more than 30 percent skeletal material. These sediments can be made up of either carbonate (or calcareous) ooze or siliceous ooze. The skeletal material in carbonate oozes is calcium carbonate usually in the form of the mineral calcite but sometimes

biogeochemical cycle, any of the natural pathways by which essential elements of living matter are circulated. The term biogeochemical is a contraction that refers to the consideration of the biological, geological, and chemical aspects of each cycle. Elements within biogeochemical cycles flow in

biogeochemistry, the study of the behaviour of inorganic chemical elements in biological systems of geologic scope as opposed to organic geochemistry, which is the study of the organic compounds found in geologic materials and meteorites, including those of problematic biological origin. Topics

biogeographic region, area of animal and plant distribution having similar or shared characteristics throughout. It is a matter of general experience that the plants and animals of the land and inland waters differ to a greater or lesser degree from one part of the world to another. Why should this

biogeography, the study of the geographic distribution of plants, animals, and other forms of life. It is concerned not only with habitation patterns but also with the factors responsible for variations in distribution. Strictly speaking, biogeography is a branch of biology, but physical

Miguel Barnet: …Biografía de un cimarrón (1966; Biography of a Runaway Slave, also published as The Autobiography of a Runaway Slave), a trend-setting book that inaugurated and then became the standard for what was to be known as testimonio, or testimonial narrative, in Latin America. In these works, a subject who has…

Germán Arciniegas: …as Biografía del Caribe (1945; Caribbean, Sea of the New World) and El continente de siete colores (1965; Latin America: A Cultural History) introduced an international audience to Arciniegas’s panoramic view of his continent.

Max Frisch: …guilt, and Biografie (published 1967; Biography), which deals with social relationships and their limitations.

Biograph Company, one of the major American motion-picture studios in the early days of filmmaking, founded as the American Mutoscope Company in 1895. It was known for many of its early production efforts, including filming U.S. presidential candidate William McKinley on the campaign trail in 1896,

John Dillinger: …trio ultimately went to the Biograph Theater. Although Sage was later described as “the woman in red,” she was actually wearing an orange skirt to make herself easily visible. After a showing of the crime drama Manhattan Melodrama (1934), Dillinger emerged to find FBI agents waiting for him. He attempted…

A.S. Byatt: The Biographer’s Tale (2000) is an erudite and occasionally esoteric literary mystery, and The Children’s Book (2009), following the family of a beloved children’s author, incorporates historical figures into a sweeping turn-of-the-20th-century tale. Ragnarok: The End of the Gods (2011), a retelling of the Norse…

Biographia Literaria, work by Samuel Taylor Coleridge, published in two volumes in 1817. Another edition of the work, to which Coleridge’s daughter Sara appended notes and supplementary biographical material, was published in 1847. The first volume of the book recounts the author’s friendship with

Biographia Literaria, work by Samuel Taylor Coleridge, published in two volumes in 1817. Another edition of the work, to which Coleridge’s daughter Sara appended notes and supplementary biographical material, was published in 1847. The first volume of the book recounts the author’s friendship with

encyclopaedia: Biography: The first real effort toward a specialized encyclopaedia was made in the mid-18th century, and the subject field that it treated was biography. The Allgemeines Gelehrten-Lexicon (1750–51; “General Scholarly Lexicon”) was compiled by Christian Gottlieb Jöcher, a German biographer, and issued by Gleditsch, the…

John Venn: In 1897 Venn published Biographical History of Gonville and Caius College, 1349–1897; his Alumni Cantabrigienses (1922), compiled with the help of his son, is a historical list of students, alumni, and officials of Cambridge from its founding to 1900.

military intelligence: Biographical: This is information collected on the views, traits, habits, skills, importance, relationships, health, and professional history of the leaders and important individuals of a nation. Biographical intelligence is important to those who must decide whether to support a foreign leader. For example, when Fidel…

biography, form of literature, commonly considered nonfictional, the subject of which is the life of an individual. One of the oldest forms of literary expression, it seeks to re-create in words the life of a human being—as understood from the historical or personal perspective of the author—by

Alphonse de Lamartine: Early life and Méditations poétiques: …published the two volumes of Harmonies poétiques et religieuses, a sort of alleluia, filled with deist—and even occasionally Christian (“L’Hymne au Christ”)—enthusiasm.

encyclopaedia: Biography: Michaud was responsible for the Biographie universelle (1811–62; “Universal Biography”). These two great works were to a certain extent competitive, which helped to improve their coverage and content; they are still used in research libraries. After their publication, the task of recording biographical information on a universal scale reverted to…

François-Joseph Fétis: …lasting importance is his eight-volume Biographie universelle des musiciens . . . (1835–44; “Universal Biography of Musicians”), which, although marred by numerous inaccuracies, remains an invaluable research tool. He also wrote extensively on musical instruments and music history and theory. Despite his sometimes fanciful or unsupported facts and opinions, Fétis’…

biography, form of literature, commonly considered nonfictional, the subject of which is the life of an individual. One of the oldest forms of literary expression, it seeks to re-create in words the life of a human being—as understood from the historical or personal perspective of the author—by

Max Frisch: …guilt, and Biografie (published 1967; Biography), which deals with social relationships and their limitations.

Miguel Barnet: …Biografía de un cimarrón (1966; Biography of a Runaway Slave, also published as The Autobiography of a Runaway Slave), a trend-setting book that inaugurated and then became the standard for what was to be known as testimonio, or testimonial narrative, in Latin America. In these works, a subject who has…

bioherm, ancient organic reef of moundlike form built by a variety of marine invertebrates, including corals, echinoderms, gastropods, mollusks, and others; fossil calcareous algae are prominent in some bioherms. A structure built by similar organisms that is bedded but not moundlike is called a

trans fat: Food products containing trans fat: …fats through the process of biohydrogenation. These microorganism-produced trans fats are found in dairy products, such as cheese and butterfat, and in certain types of meat, including lamb and beef.

Parallel Lives, influential collection of biographies of famous Greek and Roman soldiers, legislators, orators, and statesmen written as Bioi parallëloi by the Greek writer Plutarch near the end of his life. By comparing a famous Roman with a famous Greek, Plutarch intended to provide model

Gordian I: …writer Flavius Philostratus dedicated his Lives of the Sophists to him. Early in 238, when Gordian was proconsul in Africa, a group of wealthy young landowners resisted and killed the tax collectors who had been sent to Africa by the emperor Maximinus (reigned 235–238). The insurgents proclaimed Gordian emperor, and…

bioinformatics, a hybrid science that links biological data with techniques for information storage, distribution, and analysis to support multiple areas of scientific research, including biomedicine. Bioinformatics is fed by high-throughput data-generating experiments, including genomic sequence

Tatiana Bilbao: …was a multiuse biotechnology facility, Bioinnova (completed in 2012), that Bilbao and her team designed for the Monterrey Institute of Technology’s campus there. Like Bilbao’s other work, Bioinnova was inspired by a mix of geometry and nature—in this case, the form of a tree. Rather than producing a standard Modernist…

Bioko, island of Equatorial Guinea, western Africa, lying in the Bight of Biafra (Gulf of Guinea) about 60 miles (100 km) off the coast of southern Nigeria and 100 miles (160 km) northwest of continental Equatorial Guinea. In 1973 the island, then called Fernando Po, was renamed Macias Nguema

Christian fundamentalism: The late 19th to the mid-20th century: …(founded in 1886) and the Bible Institute of Los Angeles (founded in 1908), not only provided instruction to their students but assumed many of the duties formerly performed by denominational institutions. They published periodicals, broadcast from their own radio stations, held conferences, and maintained a staff of extension speakers. Indeed,…

biolith, any sediment formed from the remains of living organisms or through the physiological activities of organisms. Bioliths are sometimes identifiable as fossil plants or

synthetic biology: History of synthetic biology: …led to the production of biologic drugs, agents made from proteins and other organic compounds produced by bacteria with recombinant DNA; one such compound is synthetic insulin. However, because genetic engineering uses existing genes and bacteria, it has technical limitations and is expensive.

Biological Weapons Convention (BWC), international treaty that bans the use of biological weapons in war and prohibits all development, production, acquisition, stockpiling, or transfer of such weapons. The convention was signed in London, Moscow, and Washington, D.C., on April 10, 1972, and

physical anthropology, branch of anthropology concerned with the origin, evolution, and diversity of people. Physical anthropologists work broadly on three major sets of problems: human and nonhuman primate evolution, human variation and its significance (see also race), and the biological bases of

nanotechnology: Bioassays: A second area of intense study in nanomedicine is that of developing new diagnostic tools. Motivation for this work ranges from fundamental biomedical research at the level of single genes or cells to point-of-care applications for health delivery services. With advances in molecular biology,…

classification, in biology, the establishment of a hierarchical system of categories on the basis of presumed natural relationships among organisms. The science of biological classification is commonly called taxonomy

biological rhythm: …environmental stimulus is termed a biological clock. When an animal that functions according to such a clock is rapidly translocated to a geographic point where the environmental cycle is no longer synchronous with the animal’s cycle, the clock continues for a time to function synchronously with the original environmental cycle.…

coloration, in biology, the general appearance of an organism as determined by the quality and quantity of light that is reflected or emitted from its surfaces. Coloration depends upon several factors: the colour and distribution of the organism’s biochromes (pigments), particularly the relative

community, in biology, an interacting group of various species in a common location. For example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community. A brief treatment of biological communities follows.

biological control, the use of living organisms to control pests. A natural enemy such as a parasite, predator, or disease organism is introduced into the environment of a pest or, if already present, is encouraged to multiply and become more effective in reducing the number of pest organisms.

biological rhythm, periodic biological fluctuation in an organism that corresponds to, and is in response to, periodic environmental change. Examples of such change include cyclical variations in the relative position of Earth to the Sun and to the Moon and in the immediate effects of such

biological determinism, the idea that most human characteristics, physical and mental, are determined at conception by hereditary factors passed from parent to offspring. Although all human traits ultimately are based in a material nature (e.g., memorizing a poem involves changing molecular

biological development, the progressive changes in size, shape, and function during the life of an organism by which its genetic potentials (genotype) are translated into functioning mature systems (phenotype). Most modern philosophical outlooks would consider that development of some kind or other

biodiversity, the variety of life found in a place on Earth or, often, the total variety of life on Earth. A common measure of this variety, called species richness, is the count of species in an area. Colombia and Kenya, for example, each have more than 1,000 breeding species of birds, whereas the

Columbian Exchange: …a more general process of biological globalization that followed the transoceanic voyaging of the 15th and 16th centuries. Ecological provinces that had been torn apart by continental drift millions of years ago were suddenly reunited by oceanic shipping, particularly in the wake of Christopher Columbus’s voyages that began in 1492.…

malformation, in biology, irregular or abnormal structural development. Malformations occur in both plants and animals and have a number of causes. The processes of development are regulated in such a way that few malformed organisms are found. Those that do appear may, when properly studied, shed

membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. The outer boundary is the plasma membrane, and the compartments enclosed by internal membranes are called organelles. Biological membranes have three primary functions: (1) they

biomolecule, any of numerous substances that are produced by cells and living organisms. Biomolecules have a wide range of sizes and structures and perform a vast array of functions. The four major types of biomolecules are carbohydrates, lipids, nucleic acids, and proteins. Among biomolecules,

oceanography: Marine ecology, also called biological oceanography, involves the study of the plants and animals of the sea, including life cycles and food production.

alcohol: Biological oxidation: All substances are toxic if taken in large enough quantities, and alcohols are no exception. Although ethanol is less toxic than methanol, it is nonetheless a poisonous substance, and many people die each year from ethanol poisoning. When someone is suffering from mild…

reproductive behaviour: Natural selection and reproductive behaviour: …favourable rather than less favourable period will eventually dominate succeeding generations. This is the basis for the seasonality of reproduction among most animal species.

toxin, any substance poisonous to an organism. The term is sometimes restricted to poisons spontaneously produced by living organisms (biotoxins). Besides the poisons produced by such microorganisms as bacteria, dinoflagellates, and algae, there are toxins from fungi (mycotoxins), higher plants

estuary: Primary productivity: The high level of plant production in estuaries supports a correspondingly high level of production of invertebrate animals and fish. Estuaries often contain beds of shellfish such as mussels and oysters and large populations of shrimps and crabs. Fish such as plaice and flounders

biological psychology, the study of the physiological bases of behaviour. Biological psychology is concerned primarily with the relationship between psychological processes and the underlying physiological events—or, in other words, the mind-body phenomenon. Its focus is the function of the brain

global warming: Carbon dioxide: Another process, the “biological pump,” involves the uptake of dissolved CO2 by marine vegetation and phytoplankton (small free-floating photosynthetic organisms) living in the upper ocean or by other marine organisms that use CO2 to build skeletons and other structures made of calcium carbonate (CaCO3). As these organisms expire…

regeneration, in biology, the process by which some organisms replace or restore lost or amputated body parts. Organisms differ markedly in their ability to regenerate parts. Some grow a new structure on the stump of the old one. By such regeneration whole organisms may dramatically replace

Antarctica: Biological resources: Marine resources first attracted people to Antarctica and provided the only basis for commercial activity in this region for many years. More marine resource extraction takes place in the subantarctic and the rest of the Southern Ocean than in the waters of Antarctica’s…

therapeutics: Biological response modifiers: Biological response modifiers, used to treat cancer, exert their antitumour effects by improving host defense mechanisms against the tumour. They have a direct antiproliferative effect on tumour cells and also enhance the ability of the host to tolerate damage by toxic chemicals…

biological rhythm, periodic biological fluctuation in an organism that corresponds to, and is in response to, periodic environmental change. Examples of such change include cyclical variations in the relative position of Earth to the Sun and to the Moon and in the immediate effects of such

allometry, in biology, the change in organisms in relation to proportional changes in body size. An example of allometry can be seen in mammals. Ranging from the mouse to the elephant, as the body gets larger, in general hearts beat more slowly, brains get bigger, bones get proportionally shorter

biological soil crust, thin layer of living material formed in the uppermost millimetres of soil where soil particles are aggregated by a community of highly specialized organisms. Biological soil crusts are found primarily in open spaces in the dry and extremely cold regions of all continents,

David Baltimore: …worked with Dulbecco at the Salk Institute in La Jolla, California (1965–68), studying the mechanism of replication of the poliovirus.

therapeutics: Biological therapy: Blood transfusions were not clinically useful until about 1900, when the blood types A, B, and O were identified and

poetry: Major differences:

composting toilet, waterless sewage-treatment system that decomposes human excreta into an inert nitrogen-rich material similar to humus. Because they eliminate the water use associated with typical toilets, composting toilets circumvent the costs associated with traditional sewage treatment.

Feodosiya: …the earliest documented use of biological warfare.

biological weapon, any of a number of disease-producing agents—such as bacteria, viruses, rickettsiae, fungi, toxins, or other biological agents—that may be utilized as weapons against humans, animals, or plants. The direct use of infectious agents and poisons against enemy personnel is an ancient

Biological Weapons Convention (BWC), international treaty that bans the use of biological weapons in war and prohibits all development, production, acquisition, stockpiling, or transfer of such weapons. The convention was signed in London, Moscow, and Washington, D.C., on April 10, 1972, and

biological determinism, the idea that most human characteristics, physical and mental, are determined at conception by hereditary factors passed from parent to offspring. Although all human traits ultimately are based in a material nature (e.g., memorizing a poem involves changing molecular

biology, study of living things and their vital processes. The field deals with all the physicochemical aspects of life. The modern tendency toward cross-disciplinary research and the unification of scientific knowledge and investigation from different fields has resulted in significant overlap of

marine biology, the science that deals with animals and plants that live in the sea. It also deals with airborne and terrestrial organisms that depend directly upon bodies of salt water for food and other necessities of life. In the broadest sense it attempts to describe all vital phenomena

philosophy of biology, philosophical speculation about the concepts, methods, and theories of the biological sciences. The sharp increase in understanding of biological processes that has occurred since the mid-20th century has stimulated philosophical interest in biology to an extent unprecedented

bioluminescence, emission of light by an organism or by a laboratory biochemical system derived from an organism. It could be the ghostly glow of bacteria on decaying meat or fish, the shimmering radiance of protozoans in tropical seas, or the flickering signals of fireflies. The phenomenon occurs