Science terms starting with I

520 terms

Impoundment A body of water confined by a dam, dike, floodgate or other artificial barrier.
Impoundment (surface) A body of water or sludge confined by a dam, dike, floodgate, or other barrier.
Imprinting A phenomenon in which the disease phenotype depends on which parent passed on the disease gene.
Improvement Any building, structure, place, work of art, or other object constituting a physical betterment of real property, or any part of such betterment.
IMPT Important
Impulse (abbrev. IMPL) Alternate term for Upper Level System and Shortwave; a general term for any large-scale or mesoscale disturbance capable of producing…
Impulse Turbine A turbine that is driven by high velocity jets of water or steam from a nozzle directed to vanes or buckets attached to a wheel.
Impulsive noise Noise from impacts or explosions (e.g., from a pile driver, forging hammer, punch press, or gunshot), which is brief and abrupt, and its startling effects…
In attainment In compliance with air-quality standards. Areas that are in attainment have air quality that is as good as or better than specified in the National…
in Hg Inches of Mercury
in silico In a computer file. In the present context, the use of data bases of DNA and protein sequence to help answer biological questions.
In situ (in si'too) the natural or normal place; confined to the site of origin without invasion or spread to neighboring tissues.
in situ colony hybridization A procedure for screening bacterial colonies or plaques growing on plates or membranes for the presence of specific DNA sequences by the…
in situ hybridization The visualization of in vivo location of macromolecules (particularly polynucleotides and polypeptides) by the histological staining of tissue sections or…
in situ plaque hybridization See:.
In utero In the uterus.
In vitro (in VEE-troh) In the laboratory (outside the body). The opposite of in vivo (in the body).
in vitro embryo production (Abbreviation: IVEP). The combination of ovum pickup, in vitro maturation of ova, and in vitro fertilization.
In vitro fertilization (in VEE-troh FER-tih-lih-ZAY-shun) A procedure in which eggs are removed from a woman's ovary and combined with sperm outside the body to form embryos.
In vitro fertilization (IVF) The union of an egg and sperm, where the event takes place outside the body and in an artificial environment (the literal meaning of "in vitro" is "in…
in vitro maturation (Abbreviation: IVM). Culture of immature ova in the laboratory, usually until they are ready for in vitro fertilization.
in vitro mutagenesis See: directed mutagenesis.
in vitro transcription The cell-free synthesis from DNA of RNA in the test tube. Synonym: cell-free transcription.
in vitro translation The synthesis of proteins from isolated mRNA molecules in the test-tube. Synonym: cell-free translation.
In vivo In the body. The opposite of in vitro (outside the body or in the laboratory).
in vivo gene therapy The delivery of a gene or genes to a tissue or organ of a complete living individual to alleviate a genetic disorder.
In-Cloud Lightning (abbrev. IC) Lightning that takes place within the cloud.
In-migration People moving into an area.
in-situ conservation The conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings and…
inactivated agent A virus, bacterium or other organism that has been treated to prevent it from causing a disease. See: attenuated vaccine.
Inactive capacity (inactive storage) The reservoir capacity exclusive of and above the dead capacity from which the stored water is normally not available because of operating agreements or…
Inactive Storage Capacity The portion of capacity below which the reservoir is not normally drawn, and which is provided for sedimentation, recreation, fish and wildlife, aesthetic…
inbred line The product of inbreeding, i.e. the intercrossing of individuals that have ancestors in common.
inbreeding Matings between individuals that have one or more ancestors in common, the extreme condition being self-fertilization, which occurs naturally in many…
inbreeding depression The reduction in vigour over generations of inbreeding. This affects species which are normally outbreeding and highly heterozygous. See: hybrid vigour.
Incandescent These lights use an electrically heated filament to produce light in a vacuum or inert gas-filled bulb.
Incentive Zoning Provides for give and take compromise on zoning restrictions, allowing for more flexibility to provide environmental protection.
Inch-Degrees The product of inches of rainfall multiplied by the temperature in degrees above freezing (Fahrenheit Scale), used as a measure of the snowmelting…
Inches of Mercury (or in Hg) Unit of atmospheric pressure used in the United States. The name comes from the use of mercurial barometers which equate the height of a column…
Inches of Runoff The volume of water from runoff of a given depth over the entire drainage.
Incident command system The combination of facilities, equipment, personnel, procedures, and communications operating within a common organizational structure to effectively…
Incident Solar Radiation The amount of solar radiation striking a surface per unit of time and area.
Incidental take permit A permit issued under Section 10 of the Federal Endangered Species Act to private parties undertaking otherwise lawful projects that might result in the…
Incinerator Any device used to burn solid or liquid residues or wastes as a method of disposal.
Incised stream A stream that has cut its channel into the bed of the valley through degradation.
Inclined grate A type of furnace in which fuel enters at the top part of a grate in a continuous ribbon, passes over the upper drying section where moisture is removed…
Inclined Staff Gage A staff gage that is placed on the slope of a stream bank and graduated so that the scale reads directly in vertical depth.
Inclinometer An instrument, usually consisting of a metal or plastic tube, inserted in a borehole and a sensitized monitor either lowered into the tube or fixed within…
inclusion body A protein that is overproduced in a recombinant bacterium and forms a crystalline structure inside the bacterial cell.
Inclusionary zoning A system that requires a minimum percentage of lower and moderate income housing to be provided in new developments.
incompatibility 1. Genetically or physiologically determined prevention of intermating. 2. A physiological interaction resulting in graft rejection or failure. 3.
incompatibility group Plasmids must belong to different incompatibility groups to co-exist within the same cell.
incomplete digest See: partial digest.
Incomplete dominance A condition where a heterozygous offspring has a phenotype that is distinctly different from, and intermediate to, the parental phenotypes.
incomplete penetrance Where the phenotype does not allow perfect prediction of the genotype as a result of interference in gene expression by the environment.
INCR Increase
Incremental energy costs The cost of producing and transporting the next available unit of electrical energy.
Incremental loss of life A measurement for assessing damage after a dam fails. The difference between the projected loss of life had the dam not been built and the projected loss…
Incremental Price The additional price of an alternative fuel vehicle over a similar conventional vehicle.
incubation 1. The hatching of eggs by means of heat, either natural or artificial. 2. Period between infection and appearance of symptoms induced by a pathogen. 3.
incubator An apparatus in which environmental conditions (light, photoperiod, temperature, humidity, etc.
INDC Indicate
indehiscent Describing a fruit or fruiting body that does not open to release its seeds or spores when ripe.
Independent assortment The random distribution during meiosis of alleles (at different genes) to the gametes that is the case when the genes in question are located on different…
Independent Power Producer A company or individual that is not directly regulated as a power provider. These entities produce power for their own use and/or sell it to regulated…
Independent Power Producer (IPP) Non-utility owned electric resources. A non-utility power generator that is not a regulated utility, government agency, or qualifying facility (QF) under…
Independent System Operator (ISO) An independent, Federally regulated entity established to coordinate regional transmission in a non-discriminatory manner and ensure the safety and…
indeterminate growth The condition in which the terminal bud persists and produces successive lateral branches over an indefinite period. Opposite: determinate growth.
Index Statistical measure of the state of the stock market or economy based on the performance of stocks or other components.
Index of Wetness The ratio of precipitation for a given year over the mean annual precipitation.
Indian Summer An unseasonably warm period near the middle of autumn, usually following a substantial period of cool weather.
Indian trust assets Lands, natural resources, or other assets held in trust or restricted against alienation by the United States for Native American tribes or individual…
Indian trust resources Those natural resources, either on or off Indian lands, retained by or reserved by or for Indian tribes through treaties, statutes, judicial decisions…
Indicator Organism, species, or community which indicates certain environmental conditions.
Indigenous Native to a given area.
Indirect effects Secondary effects that occur in locations other than that of the initial action or significantly later in time.
indirect embryogenesis Plant embryo formation on callus tissues derived from explants, including zygotic or somatic embryos and seedlings. Opposite: direct embryogenesis.
Indirect Flood Damage Expenditures made as a result of the flood (other than repair) such as relief and rescue work, removing silt and debris, etc.
Indirect Hit Generally refers to locations that do not experience a direct hit from a tropical cyclone, but do experience hurricane force winds (either sustained or…
Indirect impacts Impacts that occur away from the place of origin. Effects that are related to, but removed from, a proposed action by an intermediate step or process.
Indirect liquefaction Conversion of biomass to a liquid fuel through a synthesis gas intermediate step.
indirect organogenesis Plant organ formation on callus tissues derived from explants . Opposite: direct organogenesis.
Indirect Solar Gain System A passive solar heating system in which the sun warms a heat storage element, and the heat is distributed to the interior space by convection, conduction…
Indirect Solar Water Heater These systems circulate fluids other than water (such as diluted antifreeze) through the collector.
Indomethacin (IN-doh-MEH-thuh-sin) A drug that reduces pain, fever, swelling, and redness. It is also being used to reduce tumor-induced suppression of the immune…
Induced pluripotent stem cells Adult cells reprogrammed to an embryonic stem cell–like state by being forced to express factors important for maintaining the "stemness" of embryonic…
Induced Radioactivity Radioactivity that is created by bombarding a substance with neutrons in a reactor or with charged particles produced by particle accelerators.
inducer A low-molecular-weight compound or a physical agent that associates with a repressor protein to produce a complex that can no longer bind to the operator.
inducible A gene or gene product whose transcription or synthesis is increased by exposure of the cells to an inducer or to a condition, e.g. heat.
inducible enzyme An enzyme that is synthesized only in the presence of the substrate that acts as an inducer.
inducible gene A gene that is expressed only in the presence of a specific metabolite, the inducer.
inducible promoter The activation of a promoter in response to either the presence of a particular compound, i.e. the inducer, or to a defined external condition, e.g.
Induction The act or process of causing some specific effect to occur; for example the transcription of a specific gene or operon, or the production of a protein by…
Induction Generator A device that converts the mechanical energy of rotation into electricity based on electromagnetic induction.
induction media 1. Media used to induce the formation of organs or other structures. 2. Media causing variation or mutation in the tissues exposed to it.
Induction Motor A motor in which a three phase (or any multiphase) alternating current (i.e. the working current) is supplied to iron-cored coils (or windings) within the…
Induration The hardening of a rock, usually sedimentary, by drying, pressure, or cementation.
Industrial Consumption The quantity of water consumed in a municipality or district for mechanical, trade, and manufacturing purposes, in a given period, generally one day.
Industrial Process Heat The thermal energy used in an industrial process.
Industrial sector Construction, manufacturing, agricultural and mining establishments.