Science terms starting with G

542 terms

G Abbreviation for guanine.
G cap The 5'-terminal methylated guanine nucleoside that is present on many eukaryotic mRNA s. It is joined to the mRNA, via a 5'?
G protein Proteins found on the inner surface of the plasma membrane, which bind to the guanine nucleotides, GTP and GDP.
G-protein coupled receptor See: G protein.
G/KG Grams per Kilogram
Gabion Wire basket, filled with stones, used to stabilize banks of a water course and to enhance habitat.
Gabion dam Special name given to a crib dam when built with gabions. See dam.
Gage (1) A device for indicating the magnitude or position of a thing in specific units, when such magnitude or position undergoes change, for example: The…
Gage Datum The arbitrary zero datum elevation which all stage measurements are made from.
Gage Height The water-surface elevation referred to some arbitrary gage datum. Gage height is often used interchangeably with the more general term stage, although…
Gage height (G.H.) The water surface elevation referred to some arbitrary gage datum. Gage height is often used interchangeably with the more general term "stage," although…
Gage Zero The elevation of zero stage. (Same as gage datum.)
Gaging Station A particular site on a stream, canal, lake, or reservoir where systematic observations of hydrologic data are obtained.
Gaining stream Stream or reach that receives water from the zone of saturation.
galactan The polymer of galactose with a repeating unit of C6H10O5. Found in hemicellulose it can be hydrolyzed to galactose.
galactomannan A gum in which the structural chain is made up of D-mannose units with 1?4 linkages. The ratio of galactose to mannose is 1:2.
galactose A six-carbon sugar with the formula C6H1206. A product of hydrolysis of galactan found in the hemicellulose fraction of biomass.
Galaxy A cluster of stars held together by their own gravity, and apparently dark matter as well.
Gale An extratropical low or an area of sustained surface winds of 34 (39 mph) to 47 knots (54 mph).
Gale Warning A warning of sustained surface winds, or frequent gusts, in the range of 34 knots (39 mph) to 47 knots (54 mph) inclusive, either predicted or occurring…
gall A tumorous growth in plants. See: crown gall.
Gallery A passageway within the body of a dam, its foundation, or abutments used for inspection, foundation grouting, and/or drainage.
Gallium (Ga) A chemical element, metallic in nature, used in making certain kinds of solar cells and semiconductor devices.
Gallium Arsenide A compound used to make certain types of solar photovoltaic cells.
Gallon A unit of measure equal to four quarts or 128 fluid ounces.
Galvanize To coat a metal (especially iron or steel) with zinc. Galvanization is the process of coating a metal with zinc.
Gamete A haploid sex cell, egg or sperm, that contains a single copy of each chromosome.
gamete and embryo storage Storage of ova, sperm or fertilized embryos outside their original source. Almost invariably this means cryopreservation.
Gametes Eggs or sperm.
gametic (phase) disequilibrium In relation to any two loci, the occurrence of haplotypes (gametes) at a frequency other than that predicted from the product of the respective allele…
gametic (phase) equilibrium In relation to any two loci, the occurrence of haplotypes (gametes) at a frequency equal to the product of the frequency of the two relevant alleles .
gametoclone A plant regenerated from a tissue culture originating from gametic tissue.
gametogenesis The process of the formation of gametes.
gametophyte The phase of the plant life cycle that carries the gamete producing organs. In flowering plants, the pollen grain is the male gametophyte and the embryo…
gametophytic incompatibility A phenomenon in plants, in which a pollen grain is genetically incapable of fertilizing a particular egg, because both gametes carry the identical allele…
Gamma A unit of magnetic field intensity equal to 1 x 10.0-5 Gauss; also equal to 1 nanotelsa (nT).
gamma radiation Electromagnetic radiation emitted by radioactive decay and having energies in a range from ten thousand (104) to ten million (107) electron volts.
Gamma Ray A type of high-energy radiation that is different from an x-ray.
Gamma Rays Created by nuclear reactions, this is the most energetic electromagnetic radiation emitted by the Sun.
Gamma-interferon A type of small protein with antiviral activity, made by T lymphocytes.
Gantry An overhead structure that supports machines or operating parts, such as a gantry crane.
Gantry crane A fixed or traveling, bent-supported crane for handling heavy equipment.
gap A missing section on one of the strands of double-stranded DNA. The DNA will therefore have a single-stranded region.
Gap junctions Communicating cell-cell junctions that allow ions and small molecules to pass from the cytoplasm of one cell to the cytoplasm of another cell.
Gap Winds Strong winds channeled through gaps in the Pacific coastal ranges, blowing out into the Pacific Ocean or into the waterways of the Inside Passage.
gapped DNA A double-stranded DNA molecule with one or more internal single-stranded regions.
Gas engine A piston engine that uses gaseous fuel rather than gasoline. Fuel and air are mixed before they enter cylinders; ignition occurs with a spark.
Gas Laws The thermodynamic laws pertaining to perfect gases, including Boyle's law, Charles' law, Dalton's law and the equation of state.
Gas shift process A process in which carbon monoxide and hydrogen react in the presence of a catalyst to form methane and water.
gas transfer The rate at which gases are transferred from gas into solution, an important parameter in fermentation systems because it controls the rate at which the…
Gas turbine A type of turbine in which combusted, pressurized gas is directed against a series of blades connected to a shaft, which forces the shaft to turn to…
Gaseous supersaturation Condition of higher levels of dissolved gases in water due to entrainment, pressure increases, or heating.
Gasification The process in which a solid fuel is converted into a gas; also known as pyrolitic distillation or pyrolysis.
Gasifier A device for converting a solid fuel to a gaseous fuel.
Gasket/Seal A seal used to prevent the leakage of fluids, and also maintain the pressure in an enclosure.
Gasohol A registered trademark of an agency of the state of Nebraska, for an automotive fuel containing a blend of 10 percent ethanol and 90 percent gasoline.
Gasoline A refined petroleum product suitable for use as a fuel in internal combustion engines.
Gasoline Gallon Equivalent (GGE) The amount of fuel it takes to equal the energy content of one liquid gallon of gasoline.
gastropod a member of the class of mollusks that includes snails.
Gastrula An early animal embryo consisting of two layers of cells; an embryological stage following the blastula.
Gastrulation The process whereby the cells of the blastocyst are translocated to establish three germ layers.
Gate A device that controls the flow in a conduit, pipe, or tunnel without obstructing any portion of the waterway when in the fully open position.
Gate chamber (valve chamber) A chamber in which a guard gate in a pressurized outlet works or both the guard and regulating gates in a free-flow outlet works are located.
Gate hanger A device used to maintain a set gate opening.
Gate structure Portion of spillway between inlet channel and chute, tunnel or conduit, which contains gates, such as radial gates.
Gate valve A valve with a circular-shaped closing element that fits securely over an opening through which water flows.
Gated pipe Portable pipe with small gates installed along one side for distributing irrigation water to corrugations or furrows.
Gated spillway Overflow section of dam restricted by use of gates that can be operated to control releases from the reservoir to ensure the safety of the dam.
Gauge An instrument, usually mounted on the dashboard, used to monitor engine conditions such as fuel pressure, oil pressure and temperature, water pressure and…
Gauge (gage) Device for registering water level, discharge, velocity, pressure, etc. Thickness of wire or sheet metal.
Gauge height Elevation of water surface measured by a gauge. See gage height.
Gauge pressure Absolute pressure minus atmospheric pressure. The pressure within a closed container as measured with a gauge. Sometimes referred to as relative pressure.
Gauging station Specific location on a stream where systematic observations of hydrologic data are obtained through mechanical or electrical means. See gauge.
Gauss The unit of magnetic field intensity equal to 1 dyne per unit pole.
Gaussian Plume Model A computer model used to calculate air pollution concentrations. The model assumes that a pollutant plume is carried downwind from its emission source by…
Gaussian Puff Model A model used to calculate air pollution concentrations. The model assumes that a continuously emitted plume or instantaneous cloud of pollutants can be…
GC island A segment of double-stranded DNA that is rich in GC base pairs. This type of sequence is characteristic of eukaryotic genomic regions with a high gene…
GC-rich area Many DNA sequences carry long stretches of repeated G and C which often indicate a gene-rich region.
GDAs See Renewable Resource Generation Development Areas
GDP See Gross domestic product (GDP)
GDR On a buoy report, direction, in degrees clockwise from true North, of the GSP, reported at the last hourly 10-minute segment.
Geiger counter A Geiger-Müller detector and measuring instrument. It contains a gas-filled tube which discharges electrically when ionizing radiation passes through it…
gel support medium (agarose) that holds DNA molecules in place during the separation phase of electrophoresis.
Gel electrophoresis See: electrophoresis.
gel filtration A method of protein or DNA purification, where differences in size are used to separate the components of a complex mixture.
gelatin A glutinous, protein aceous gelling and solidifying agent. Gelatin is produced by the partial hydrolysis (via boiling) of collagen, found in the…
gelatinization The swelling of starch when added to hot water. Hydrolysis causes the molecule to lose structure, and technically gelatinization is not complete until…
GelriteTM The brand name of a Pseudomonas-derived refined polysaccharide used as a gelling agent and agar substitute.
GEM A genetically engineered microorganism.
GEMPAK General Environmental Meteorological Package (programming language)
GEN General
Gene The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a…
gene (resources) conservation The conservation of species, populations, individuals or parts of individuals, by in situ or ex situ methods, to provide a diversity of genetic materials…
gene addition The addition of a functional copy of a gene to the genome of an organism.
Gene amplification The presence of multiple genes. Amplification is one mechanism through which proto-oncogenes are activated in malignant cells.
gene bank 1. The physical location where collections of genetic material in the form of seeds, tissues or reproductive cells of plants or animals are stored. 2.
Gene chip technology Development of cDNA microarrays from a large number of genes. Used to monitor and measure changes in gene expression for each gene represented on the chip.
Gene cloning The process of synthesizing multiple copies of a particular DNA sequence using a bacteria cell or another organism as a host. See DNA, Host.
gene construct See: construct.
gene conversion A process, often associated with recombination, during which one allele is replicated at the expense of another, leading to non-Mendelian segregation…