ethanolCommonly used to disinfect plant tissues, glassware utensils and working surfaces in tissue culture manipulations; to precipitate aqueous solutions of…
ethephonA synthetic compound commonly used as a source of ethylene, a gaseous plant growth regulator.
Ethidium bromideA fluorescent dye used to stain DNA and RNA. The dye fluoresces when exposed to UV light.
ethyleneA gaseous plant growth regulator acting on various aspects of vegetative growth, fruit ripening and abscission of plant parts. Synonym: ethene.
ethylenediamine tetraacetic acid(Abbreviation: EDTA). A chelating compound. Used to keep nutrients, such as iron, bound in a soluble form that leaves them still available to the plant…
etiolationAn abnormal increase in stem elongation, accompanied by poor (if any) leaf development.
euchromatinChromosomal material that is stained less intensely by certain dyes. Thought to be the chromosomal domains which are gene-rich, since the DNA in these…
EugenicsThe application of the principles of genetics to the 'improvement' of humankind. Wholly discredited as a scientific approach since the Nazi period.
EukaryoteAn organism whose cells possess a nucleus and other membrane-bound vesicles, including all members of the protist, fungi, plant and animal kingdoms; and…
euploidAn organism or cell having a chromosome number that is an exact multiple of the haploid number.
EvapotranspirationThe net water loss (in vapour form) per unit area of land, both directly from the land surface, and indirectly through transpiring leaves.
ex vitroOrganisms removed from tissue culture and transplanted; generally plants to soil or potting mixture.
Ex vivo(ex VEE-voh) Outside of the living body. Refers to a medical procedure in which an organ, cells, or tissue are taken from a living body for a treatment or…
ex vivo gene therapyThe delivery of a gene or genes to the isolated cells of an individual, with the intention of alleviating a genetic disorder.
ex-situ conservationThe conservation of components of biological diversity outside their natural habitats.
excinucleaseThe endonuclease -containing protein complex that excises a segment of damaged DNA during excision repair.
excision repair DNArepair processes that involve the removal of a damaged or incorrect segment of one strand of double-stranded DNA and its replacement by the synthesis of a…
excitation wavelengthThe specific wavelength of light required to stimulate a fluorescent molecule, such as a labelled probe, to emit light at the (lower) emission wavelength.
excrete(ek-SKREET) To get rid of waste material from the blood, tissues, or organs by a normal discharge (such as sweat, urine, or stool).
exit site(Abbreviation: E site). The ribosome binding site that contains the free tRNA prior to its release.
exogenousProduced outside of; originating from, or due to, external causes. Opposite: endogenous.
Exogenous DNADNA that has been derived from one organism, and is to be introduced into a cell a different species. Also referred to as foreign DNA or heterologous DNA.
ExonA DNA sequence that is ultimately translated into protein. See DNA.
exonuclease III(Abbreviation: exo III). An Escherichia coli enzyme that removes nucleotides from the 3' hydroxyl ends of double-stranded DNA.
exopolysaccharideA polysaccharide that is secreted by a micro-organism into the surrounding environment.
exotoxinA toxin released by a bacterium into the medium in which it grows.
expected progeny difference(Abbreviation: EPD). The predicted performance of the future offspring of an individual for a particular trait, calculated from measurement(s) of the…
explantA portion of a plant aseptically excised and prepared for culture in a nutrient medium.
explant donorThe plant from which an explant has been taken.
explantationThe removal of cells, tissues or organs of animals and plants for observation of their growth and development in appropriate culture media.
explosion methodA technique for the genetic transformation of cells, in which the transgene is driven into the target (plant) cells by the sudden vaporization (effected…
exportData extracted or taken out of one environment or application usually in a prescribed format, and usually for import into another environment or…
ExpressTo translate a gene's message into a molecular product.
expressed sequence tag(Abbreviation: EST). Partially sequenced cDNA clone. Because the read length of a standard DNA sequencing reaction is shorter than the majority of cDNA…
Expressed sequence tag (EST)A short strand of DNA that is a part of a cDNA molecule and can act as identifier of a gene. Used in locating and mapping genes.
expression systemCombination of host and vector which provides a genetic context for making a cloned gene functional, i.e. produce peptide, in the host cell.
expression vectorA cloning vector that has been constructed in such a way that, after insertion of a DNA molecule, its coding sequence is properly transcribed and the mRNA…
expressivityDegree of expression of a trait controlled by a particular gene. The gene may show different degrees of expression in different individuals.
extensionThe short single-stranded stretch of nucleotides remaining on a double-stranded DNA molecule, following treatment with a restriction endonuclease which…
Extracellular matrixThe microenvironment next to a cell that allows for structural support, orientation, and connections for cell-to-cell interactions and formation of…
extrachromosomalIn eukaryotes, non-nuclear DNA, present in cytoplasm organelles such as mitochondria and chloroplasts . In prokaryotes, non-chromosomal DNA, i.e. plasmids.
Extraembryonic tissuesIntrauterine tissues that support the embryo's placenta, umbilical cord, and amniotic sac.
extranuclear genesGenes residing elsewhere than in the nucleus (e.g. in mitochondria, chloroplasts or plastids).
exudeSlowly discharge liquid material (such as tannins or oxidized polyphenols from plant material) through pores or cuts, or by diffusion into the medium.
F factorAbbreviation for fertility factor. A bacterial plasmid that confers the ability to function as a genetic donor in conjugation. See: Hfr.
F1Abbreviation for filial generation 1. The initial hybrid generation resulting from a cross between two parents. See Fn.
F1, F2, FnSubsequent hybrid generations, counting from the F1. Thus, for example, F4 describes the progeny of the F3, which is the progeny of the F2 generation…
F2The second hybrid generation, produced either by intercrossing two F1 individuals, or by self-fertilizing an F1 individual. See Fn.
FABA product of hydrolysis of an IgG antibody, consisting of the variable region with some of the constant region of a heavy chain, and an entire light chain.
factorial matingA mating scheme in which each male parent is mated with each female parent. Made possible in animals by means of in vitro embryo production.
facultative anaerobeAn organism that will grow under either aerobic or anaerobic conditions.
False negativetest result that states that an analyte is absent, when, in fact, it is present above the established limit of detection for the analyte in question.
false positivetest result that states that an analyte is present, when, in fact, it is not present or, is present in an amount less than a threshold or designated…
familial Mediterranean feverAn inherited disease whose chief symptoms are recurrent fevers and severe abdominal pain due to inflammation of the abdominal cavity.
farm animal genetic resourcesThose animal species that are used, or may be used, for the production of food and agriculture, and the populations within each of them.
farmers' privilegeRights to hold germplasm, covered by plant variety protection, as a seed source for subsequent seasons.
farmers' rightsRights first recognized by Resolution 5 of the 1989 FAO Conference as "rights arising from the past, present and future contributions of farmers in the…
FCA product of hydrolysis of an IgG antibody, consisting of parts of the constant regions of two heavy chains held together by a disulphide bridge, but…
FDAAn agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are…
fed-batch fermentationCulture of cells or micro-organisms where nutrients are added periodically to the bioreactor.
feedback inhibitionThe process by which the accumulated end product of a biochemical pathway stops synthesis of that product.
Feeder cell layerCells that are utilized in co-culture to maintain pluripotent stem cells. Cells usually consist of mouse embryonic fibroblasts.
Feeder layerCells used in co-culture to maintain pluripotent stem cells. Cells usually consist of mouse embryonic fibroblasts.
FeralRefers to an individual or population that has returned to the wild after a history of domestication.
FermentationThe anaerobic breakdown of complex organic substances, especially carbohydrates, by micro-organisms, yielding energy.
fermentation substratesMaterials used as food for growing micro-organisms. The fermentation substrates and the trace materials needed, together with chemicals added to make the…