Biological magnification (biomagnification)Step by step concentration of substances in successive levels of food chains. The enhancement of a substance (usually a contaminant) in a food web such…
Biological Opinion (BO)Document stating the U.S. Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) opinion as to whether a Federal action is…
Biological oxygen demand(Abbreviation: BOD). The dissolved oxygen required for the respiration of a population of aerobic organisms present in water.
Biological processesProcesses characteristic of, or resulting from, the activities of living organisms.
Biological soil crustsCommonly found in semiarid and arid environments, biological soil crusts are formed by living organisms and their by-products, creating a crust of soil…
BiologicsAgents, such as vaccines, that give immunity to diseases or harmful biotic stresses.
BiomassThe aggregate amount of living matter or a specific species within a specific habitat, or the total number of a specific species in a specific habitat.
Biomass energyEnergy produced by the conversion of biomass directly to heat or to a liquid or gas that can be converted to energy.
Biomass FuelBiomass converted directly to energy or converted to liquid or gaseous fuels such as ethanol, methanol, methane, and hydrogen.
Biomass GasificationThe conversion of biomass into a gas, by biogasification (see above) or thermal gasification, in which hydrogen is produced from high-temperature…
biomass processing residuesByproducts from processing all forms of biomass that have significant energy potential.
BiomeA major ecological community or complex of communities, extending over a large geographical area and characterized by a dominant type of vegetation.
biometry(by-AH-meh-tree) The science of collecting and analyzing biologic or health data using statistical methods.
biomimetic materialsEmployed to describe synthetic analogues of natural materials with advantageous properties.
biopesticideA compound that kills organisms by virtue of specific biological effects rather than as a broader chemical poison.
BiopharmingThe use of genetically transformed crop plants and livestock animals to produce valuable compounds, especially pharmaceuticals.
BiophotolysisThe action of light on a biological system that results in the dissociation of a substrate, usually water, to produce hydrogen.
biopiracyThe patenting of genetic stocks, and the subsequent privatization of genetic resources collections.
biopolymerAny large polymer (protein, nucleic acid, polysaccharide) produced by a living organism.
bioprocessAny process that uses complete living cells or their components (e.g. enzymes, chloroplasts ) to effect desired physical or chemical changes.
bioreactorA tank in which cells, cell extracts or enzymes carry out a biological reaction. Often refers to a fermentation vessel for cells or micro-organisms.
biorecoveryThe use of micro-organisms for the recovery of valuable materials (metals or particular organic compounds) from complex mixtures.
BioremediationThe use of microorganisms to remedy environmental problems. See Bioaugmentation, Bioenrichment.
Bioretention SystemThe bioretention system (also referred to as a "rain garden" or a "biofilter") is a stormwater management practice to manage and treat stormwater runoff…
biosafetyReferring to the avoidance of risk to human health and safety, and to the conservation of the environment, as a result of the use for research and…
biosafety protocolAn inteRNA tionally agreed protocol set up to protect biological diversity from the potential risks posed by the release of genetically modified organisms.
biosensorA device that uses an immobilized biologically-related agent (such as an enzyme, antibiotic, organelle or whole cell) to detect or measure a chemical…
biosilkA biomimetic fibre produced by the expression of the relevant orb-weaving spider genes in yeast or bacteria, followed by the spinning of the expressed…
biosorbentsMicro-organisms which, either by themselves or in conjunction with a substrate are able to extract and/or concentrate a desired molecule by means of its…
BiosphereThe part of the earth and its atmosphere that is inhabited by living organisms.
biosynthesisSynthesis of compounds by living cells, which is the essential feature of anabolism.
BiotaThe animal and plant life of a region or period.
BiotechnologyThe scientific manipulation of living organ- isms, especially at the molecular genetic level, to produce useful products.
Biotechnology-derivedThe use of molecular biology and/or recombinant DNA technology, or in vitro gene transfer, to develop products or to impart specific capabilities in…
Biotic communityA naturally occurring, interdependent community of plants and animals that live in the same environment.
biotic factorOther living organisms that are a component of an organism's environment, and form the biotic environment, affecting the organism in many ways.
Biotic potentialInherent capacity of an organism to reproduce and survive, which is pitted against limiting influences of the environment.
Biotic pyramidSet of all food chains or hierarchic arrangements of organisms as eaters and eaten in a prescribed area when tabulated by numbers or by biomasses, usually…
Biotic stressLiving organisms which can harm plants , such as viruses, fungi, and bacteria, and harmful insects. See Abiotic stress.
biotinA vitamin of the B complex, it acts as a co-enzyme for various enzymes that catalyse the incorporation of carbon dioxide into various compounds, and is…
biotin labellingThe attachment of biotin to another molecule, especially DNA.
biotinylated-DNAA DNA molecule labelled with biotin by incorporation of a biotinylated nucleotide (usually uracil ) into a DNA molecule.
biotoxinA naturally produced compound which shows pronounced biological activity, toxic to some or many organisms.
biotransformationThe conversion of one chemical or material into another using a biological catalyst : a near synonym is biocatalysis, and hence the catalyst used is…
BiotypeGenetically homogeneous population composed only of closely similar individuals; a genotypic race or group of organisms.
bipolar see-sawthe occurrence of warm temperatures in the Southern Hemisphere while temperatures in the Northern Hemisphere are colder-than-average, or vice versa.
Birth defectA structural, functional, or metabolic abnormality present at birth that results in physical or mental disability or is fatal.
BitumenGooey, black, high-sulfur, heavy oil extracted from tar sand and then upgraded to synthetic fuel oil. See tar sand.
Bituminous coalA dense, black, soft coal, often with well-defined bands of bright and dull material.
bivalentTwo paired homologous chromosomes (one of maternal origin; the other of paternal origin) at prophase to anaphase of the first meiotic division.
BLAbbreviation for Boundary Layer; a layer of air adjacent to a bounding surface.
Black BodyA hypothetical object that absorbs all of the radiation that strikes it; also emits radiation at a maximum rate for its given temperature.
Black Body SpectrumA plot of the intensity of radiation versus wavelength for a black body.
Black CarbonOperationally defined species based on measurement of light absorption and chemical reactivity and/or thermal stability; consists of soot, charcoal…
black carbon concentrationThe concentration of carbon in its very absorbing, elemental, non-organic, non-oxide form (e.g. graphite).
Black IceTransparent ice formed in rivers and lakes, or on roads and bridges.
Black waterLiquid and solid human body waste and the carriage water generated through toilet usage.
BlackbodyAn ideal substance that absorbs all radiation falling on it, and reflecting nothing.
Blackbody RadiationThe electromagnetic radiation emitted by an ideal blackbody adhering to the radiation laws; it is the theoretical maximum amount of electromagnetic…
BlackoutThe disconnection of the source of electricity from all the electrical loads in a certain geographical area brought about by an emergency forced outage or…
bladeUsually a part of an excavator which digs and pushes dirt but does not carry it.
blast cellA large, rapidly dividing cell that develops from a B cell in response to an antigenic stimulus.
Blasting matsA blanket usually composed of woven cable or interlocked rings placed over a blast to reduce flyrock.
BlastocoelThe fluid-filled cavity inside the blastocyst of the developing embryo.
BlastocystA mammalian embryo (fertilized ovum) in the early stages of development, approximately up to the time of implantation.
Blastocyst stageAn early stage in the development of embryos, when (in mammals) the embryo is a spherical body comprising an inner cell mass that will become the fetus…
blastomereAny one of the cells formed from the first few cleavages in animal embryology. The embryo usually divides into two, then four, then eight blastomeres, and…
BlastulaIn animals, an early embryo form that follows the morula stage; typically, a single-layered sheet (blastoderm) or ball of cells (blastocyst ).
bleeding1. Collection of blood from immunized animals. 2. Used to describe the occasional purplish-black colouration of media due to phenolic products given off…
Blender PumpA fuel dispenser that draws fuel from two separate storage tanks and can dispense preprogrammed blends of those two fuels.
BlightPhysical and economic conditions within an area that cause a reduction of or lack of proper utilization of that area.
Blizzard(abbrev. BLZD)- A blizzard means that the following conditions are expected to prevail for a period of 3 hours or longer: Sustained wind or frequent gusts…
Blizzard WarningIssued for winter storms with sustained or frequent winds of 35 mph or higher with considerable falling and/or blowing snow that frequently reduces…
blockA repetition/replication of the Early, Mid and Late Seral Treatment plots and a Control plot. See Repetition/replication.
Block Group (BG)(BG)A cluster of census blocks having the same first digit of their four-digit identifying numbers within a census tract.
Block-faulted (mountains)Landforms formed by the movement (uplift and tilting) of large crustal blocks during an extensional episode.
Blocked FlowFlow approaching a mountain barrier that is too weak or too stable to be carried over the barrier.
BlockloadingProviding a consistent amount of electrical power in a stated period of time.
Blood Cell SeparatorA machine, used in apheresis, which distinguishes the small fraction of stem cells in the blood from all other blood cells, so that the stem cells may be…
blotAs a verb, to transfer DNA, RNA or protein to an immobilizing matrix. As a noun, the immobilizing matrix carrying DNA, RNA or protein.
BlowdownPeriodic removal of water from an evaporative cooling system (also known as a wet closed-cycle cooling system) to control the buildup of impurities and…