Glossary

Agrobacterium: Microorganism (bacterium) that produces crown gall disease in the wild; it does so by introducing a part of its genetic material into the plant to direct it to make compounds it needs to live. A small piece of genetic material was isolated from this bacterium, modified so that it does not cause disease and is now used for introducing new genetic information into plant cells.

Agro-ecosystem: A complex mixture of pastures, farm fields, businesses, home sites, natural habitats and cities and towns.

Agronomy: The science and economics of crop production; management of farm land.

Allergen: A substance, usually a protein, which stimulates an allergic response in susceptible individuals.

Allergy: State or condition, characterized by an unusual sensitivity to a material or substance that results in a range of different effects from mild respiratory problems, to a fatal allergic reaction (anaphylaxis).

Amino acid: Building blocks that are linked together to form a protein. Humans and animals cannot produce eight of them and must eat food sources to receive them.

Animal husbandry: Practice of breeding, feeding and caring for animals to maximize the desired characteristics.

Antibiotic: A substance produced by microorganisms that is capable of killing or inhibiting growth of other microorganisms.

Antibody: A blood protein produced in response to invasion of the body by an antigen (foreign substance, such as organisms) that has the capacity to neutralize the antigen.

Antigen: Substance that stimulates the immune system and the production of antibodies.

Asexual reproduction: Any form of propagation that does not involve the combining of eggs and sperm or pollen (see sexual reproduction).

Bacillus thuringiensis (Bt): A bacterium commonly found in soils that has been used extensively in pest control as a foliar spray. Certain specific genes from the bacterium can be transferred into plants which then produce a protein that kills specific classes of insects. It is not believed to cause any problems in other organisms and is not known to cause allergies or toxicity when eaten.

Bacteria: Single-celled microbes, including pathogens, (organisms that can cause disease) beneficial microorganisms (e.g., digestive flora in the intestinal tract) and organisms like E. coli that can be manipulated in the laboratory to study genetic information.

Binary system: Method of gene transfer using two vectors, one containing the gene(s) and the other containing machinery needed for gene transfer.

Biochemistry: Branch of science dealing with the chemistry of life processes occurring in living organisms.

Biodegradable: A substance that can be decomposed through the action of living organisms. The substance is broken down into carbon dioxide and water.

Biodiversity: The variety of life forms at different levels, from genes to species, and in all environments, aquatic and terrestrial.

Bioinformatics: Discipline concerned with the development of methods for collection, storage and analysis of information from sequences, maps, structures, functions or other types of information generated in molecular biology and genetics experiments.

Biolistics: Physical method for transferring genes into cells. Microparticles, such as gold or tungsten, are coated with DNA and projected into the cell using a high-velocity "gene gun".

Biological control: Combating harmful pests with beneficial organisms, such as parasites or predators, instead of using chemical pesticides. Also referred to as biocontrol.

Biomass: The total amount of living material in a given environment, often expressed in weight per unit area or organic matter produced by the plant per unit area.

Bioremediation: A method of using living organisms, such as microbes, plants and fungi to assist in removing, breaking down or stabilizing harmful contaminants in the soil, water or air. Also called phytoremediation or, for plants, green remediation.

Biotechnology: Often used synonymously with recombinant DNA technology or genetic engineering, although it actually refers to a collection of technologies encompassing manipulation of cells, tissues or organisms to produce useful substances or perform certain functions, such as fermentation, tissue culture and recombinant DNA technology.

Bt: See Bacillus thuringiensis.

Callus: Undifferentiated mass of plant cells, often produced during tissue culture, that is capable of regenerating and developing into an entire organism. Cells of the callus are thought to be totipotent, that is to have all the genetic information needed to produce the entire organism.

Cell: The smallest independent unit capable of performing all life functions. Consists of a mass of fluid material bounded by a membrane and containing a nucleus in higher organisms (bacteria do not contain a nucleus but are bounded by a membrane).

Cell culture: Process of growing cells from multicellular organisms isolated from the organism and grown in the laboratory in a sterile, nutrient-containing culture medium.

Chromosome: Individual packages of the genetic material, or DNA, inside the nucleus of cells. The number of chromosomes is species-specific and in humans is forty-six.

Clone: Individuals derived asexually from the same single parent or ancestor and therefore genetically identical to it, except when mutations occur.

Containment: Regulations designed to limit the spread of recombinant organisms and genes.

Cotyledon: Seed leaf that emerges from the seed after germination. It is part of the embryo in the seed itself and serves as a storage material in many plants. In dicots (plants with two seed leaves), it first emerges from the seed and helps feed the growing plant.

Cross-pollination: Transfer of pollen (male portion of plant used in reproduction) from one flower to a flower on a different plant.

Cultivar: Also called a variety. A group of related plants, derived from a wild species that was selected by farmers for agricultural uses; a product of artificial selection. No particular level of genetic similarity is implied.

Culture: Either a group of microorganisms or plant or animal cells that are being grown in the laboratory.

Cytoplasm: The gel-like material contained within a cell, external to the nuclear membrane, which contains all the cellular internal organelles.

Dietary supplement: Any nutrient added to the diet to improve its nutritional value.

DNA (deoxyribonucleic acid): Chemical that comprises the genetic material of most organisms except for some viruses that use RNA as the genetic material.

Dominant trait: Visible characteristic or feature that is displayed when at least one of the two copies of the gene that an organism contains is for this particular feature.

Ecosystem: Community of organisms and their physical environment interacting as an ecological unit. The many different communities that make up the world are all ecosystems.

Embryo: Organism at its earliest stage of development; in plants it's the initial structures that form inside the seed and in animals it is the organism in its earliest stage in the mother's womb.

Enzyme: Usually a protein that promotes a specific reaction in living organisms, such as the enzyme amylase in saliva that breaks down starch to sugar. The enzyme does not provide any energy for the reaction but rather it acts to speed up the reaction.

Expression: Manifestation of an inheritable characteristic as controlled by its corresponding gene(s).

Fermentation: Cellular process where cells partially break down sugars and other substances releasing energy, producing carbon dioxide and converting them, for example, to alcohol, lactic acid or vinegar.

Fungicide: Chemical substance used to control the growth of fungi or fungal infections.

Fungus: One of many different organisms, like mushrooms, molds and yeasts, sometimes, imprecisely, called plants, but without chlorophyll and without using sunlight to produce its food.

Gene: A unit of heredity. Specific segment of DNA that directs the production of a specific protein or controls a specific function of a cell. Different forms of same gene, called alleles, exist in populations.

Gene flow: Movement of genes from one plant population to another via sexual reproduction.

Gene gun: Device that propels DNA-coated heavy metal particles directly into the plant cell to accomplish genetic engineering. See biolistics.

Genetic code: Sets of three consecutive chemical building blocks (nucleotides) that comprise DNA and RNA and which determines the order that the building blocks of protein (amino acids) will be linked together.

Genetic diversity: Total number of different genetic characteristics in the genetic makeup of a population or species.

Genetic engineering: Laboratory process for transferring genes from one organism to another organism not sexually compatible with the first organism. The process is extremely accurate and is controlled by extensive federal regulations.

Genetic modification: Broad term covering both plant breeding and recombinant DNA technology. Sometimes used specifically to refer to recombinant DNA techniques.

Genetically modified organism (GMO): Popular term for an organism that contains new genetic material introduced by recombinant DNA techniques. Also referred to as a transgenic organism. It is distinguished from organisms produced by traditional plant or animal breeding.

Genetics: Study of genes, hereditary units containing the DNA instructions for making all of the proteins in an organism. Genetics also studies how genes are transmitted from one generation to the next.

Genome: All of the genes in an organism; the entire genetic material of an organism.

Genomics: Study of genes and their functions. More specifically, it studies how organisms' genomes are organized and the role that different regions of the genome play in different cellular functions.

Germination: Process of beginning to grow or develop. In plants, it is generally the process of a seed sprouting and producing a seedling and root system. In microbes, it refers to the transition of a spore to an active cell.

Germplasm: Material that contains genetic information (genes) and serves to transmit it from one generation to another.

Growth hormone: Substance made by an organism that controls growth. It can be produced by a specific organ or it can act throughout the organism.

Herbal supplement: Concentrated plant extracts, which are used to prevent disease or to cure illness.

Herbicide: A substance, usually a chemical, used to eliminate or control the growth of plant weeds by specifically attacking particular enzymes in the weed.

Heredity: Transmission of traits from parents to progeny.

Hormone: Substance that affects biological processes and functions in a specific way. Term often used to describe chemicals produced in one tissue in the body that affects cells in other tissues and is usually transported through the blood system.

Host: Organism that is infected or attacked by another organism, such as a microbe or parasite.

Hybrid: Progeny resulting from a genetic cross between genetically dissimilar parents.

Hybridization: Breeding between two different species (interspecific hybridization) or between individuals of a species (intraspecific hybridization).

Intellectual property: Product of the mind such as a new process or invention. It can be protected by a patent in case of a new discovery or by a copyright in the case of written material.

Integrated pest management (IPM): Crop management strategy that uses field surveillance (scouting) and selective use of pesticides to control pests and minimize hazards to people and the environment. It also relies heavily on crop rotation and use of natural predators and parasites to aid in pest control.

Inoculation: Introduction of microorganisms into the environment, into a culture medium or onto a culture plate to promote growth.

Inorganic: A compound that does not contain carbon. Most important exception to this guideline is carbon dioxide, which is generally considered inorganic, even though it contains carbon.

Insecticide: Chemical substance designed to kill or eliminate insects.

Library: In molecular biology it is the collection of cloned DNA fragments.

Marker-assisted selection: Process of selecting plants or animals for a particular trait using a gene that is linked to that trait (the marker gene). The marker gene is one that is easier to identify or select than the actual target gene for the trait of interest.

Metabolic engineering: Manipulation of metabolism (biochemical reactions occurring in cells) in an organism using specific genetic changes to achieve improved production of certain chemicals or compounds.

Metabolism: A myriad of chemical reactions that occur in a living cell or organism.

Microorganism: Also called a microbe. It is an organism too small to be seen with the naked eye, like bacteria, fungi, viruses and certain algae.

Mitochondria: Membrane-enclosed organelles in the cell, which are present in most higher organisms and which generate most of the cell's energy. Mitochondria have their own DNA and are inherited through the mother.

Molecule: Smallest quantity or particle of a substance that has the properties of that substance. It is made up of atoms that are bonded together in various ways.

Monoclonal antibody: Antibody with a single specificity, produced by a single type of cell (clone).

Monoculture: Agricultural practice where a single crop or variety is cultivated over a large area for a long period of time. Reduces genetic diversity that may be needed when pest or pathogen problems arise.

Mutation: Naturally-occurring or induced change in the gene or chromosome that results in a new, inheritable trait.

Nanometer: Equals one billionth of a meter (1 nm = 0.00000004 inches). Nanometer is a measure of scale not a specific technology. A nanometer is about the width of six bonded carbon atoms.

Nanotechnology: Broad term used to define science and technology that involves manipulation and fabrication at the nanometer scale (billionths of a meter). It can include various fields such as medicine, electronics, energy production and biomaterials.

Nitrogen fixation: Conversion of atmospheric nitrogen gas, which is not usable by plants, by certain microbes into nitrogenous compounds (fertilizer) that can be used by plants.

Nucleotide: Structural unit, or building block, from which DNA and RNA are made; strung together on a backbone of alternating phosphates and sugars.

Nucleus: The membrane-enclosed structure inside the cell (in most higher organisms) which contains the chromosomes and most of the genetic material.

Oligonucleotide: Short segment of DNA or RNA; usually man-made.

Organic: In chemistry it refers to any compound that contains carbon. More generally it refers to natural products that exist in nature or to food produced without using manufactured chemicals.

Organism: Any living form, including humans, animals, plants, microorganisms or virus.

Outcross: Breeding of two closely related organisms (not members of the same family or variety) to produce offspring. Also referred to as outbreeding. Opposite of inbreeding.

Pathogen: Disease-causing organism.

Pesticide: Substance used to destroy or control pests. See also herbicide, insecticide and fungicide.

Pharmaceutical: Any drug or medicinal compound.

Phenotype: The specific physical characteristics, or traits, of an organism. These properties come from both the genetic information and environmental influences. Genetically identical plants grown in different environments often have different phenotypes.

Phloem: Tissue responsible for transporting sugars and nutrients, manufactured in the leaves during photosynthesis, to different parts of the plant.

Phosphorous: Essential mineral that plants require for optimal growth.

Photosynthesis: Process that occurs in green plants where light energy is used to convert inorganic molecules (like carbon dioxide and water) into sugars that are used for energy storage. Oxygen is released as a byproduct.

Phytoremediation: See bioremediation.

Plant breeding: Science and art of improving plants by making genetic changes. It involves selection of superior individuals from a population. These superior plants (or seeds from these plants) are then used for further breeding. Process is repeated for many generations to 'fix' or stabilize the new traits. All improvements made in cultivated plants result from either directly or indirectly from this process.

Plasmid: Self-reproducing piece of DNA that exists separately from the rest of the genetic material in a cell.

Pollen: Male portion of plant used in reproduction, equivalent to sperm in animals. It is a fine, often yellow powder formed in the stamen and transported to another flower for fertilization by wind, insects, birds and other animals.

Pollination: Transfer of pollen from male organ of a flower to female organ of same or different flower, resulting in fertilization.

Polymer: Long chains of repeating smaller units (monomers). DNA (nucleotides joined into chains) and protein (amino acids joined into chains) are biological polymers. Many plastics are man-made polymers.

Population genetics: Study of changes in the genetic composition of population over time.

Protein: A large biological molecule composed of amino acids and with a variety of functions in the cell. Proteins make up structural parts of an organism, like hair, or they catalyze reactions, like enzymes, or they are used for transport or defense as antibodies.

Recombinant DNA: DNA molecule constructed by joining different DNA molecules. Tools of recombinant DNA are used to transfer and express the genetic information for a trait from one organism to another.

Regeneration: Process by which an organism re-grows an organ or appendage lost through injury or being cut. Also refers to the process of producing an entire plant from plant tissue or individual cells grown in the laboratory.

Renewable resource: Resource that is capable of being replaced through natural processes. Examples include wood, water and plant biomass.

Resistance: Ability of an organism to defend itself against a disease or to tolerate the effects of a pesticide or other substance. Resistance may be conferred by the plant's genes or the plant's environment; it may be the result of traditional breeding or genetic engineering.

Restriction enzyme: Enzyme capable of cutting DNA at specific sequences. Also referred to as restriction endonuclease or molecular scissors.

RNA (ribonucleic acid): Molecule closely related to DNA but with a single strand and not a double helix. It is used to translate the genetic code (DNA) into protein. In some organisms it serves as the hereditary material.

Sexual reproduction: Form of reproduction involving union of male (sperm or pollen) and female (egg or ovule) cells. The cell union leads to genetic diversity where the offsprings are different from one another and different from their parents.

Somaclonal variation: Genetic changes that occur within non-reproductive cells, often during the process of culturing the cells in the laboratory. Some of these changes are heritable and result from actual changes in the genetic code and some changes are only present for a single generation at which time the plant becomes phenotypically normal.

Species: Term used to describe the group of like individuals. Classically species were defined as organisms that share certain characteristics.

Somatotropin: Protein hormone secreted by a special organ in mammals, the pituitary gland, and each animal produces its own specific version of the hormone that is active in its own species and in species of lower order but not higher. The hormone directs milk production and growth.

Spore: Particular form of certain microbes that allows the organisms to survive in a dormant stage until conditions improve at which time the spores can germinate and the life cycle resumes.

Sterile: Free of living organisms; the terms usually refers to lack of microorganisms or bacteria. Process of sterilization refers to killing all life forms by heating, chemical treatment or other means.

Strain: Different organism within same species.

Substrate: Material or substance acted upon by an enzyme.

Symbiosis: Two or more dissimilar organisms living together in close association with one another. Includes parasitism, where one of the organisms harms the other(s), mutualism, where association is advantageous to all) and commensalism, where association is advantageous to one organism but doesn't affect other organism(s).

Tissue culture: Process of introducing living tissue into culture in the laboratory where tissues or cells can be grown for extended periods of time.

Totipotency: Capability of certain cells to be cultured in the laboratory and undergo sustained cell divisions. Application of hormonal and other signals triggers the tissue to undergo a programmed, developmental pathway that leads to the reformation of the entire organism.

Transformation: Process of introducing into an organism new genetic information that can be stably maintained.

Transgenic: Organism that contains genetic materials introduced through recombinant DNA techniques. Usually implies that organism contains DNA from another organism.

Transposon: Naturally occurring DNA sequence that is capable of moving its location within the genome; movement is due to the presence of an enzyme that can mediate the movement and which is encoded within the transposon itself. Transposable elements are responsible for the multiple colors on an ear of Indian corn and the color sectors in petunia.

Vaccine: Utilization of a killed or debilitated organism or a part of its contents that is capable of inducing protection against the disease caused by that organism.

Value-added: Trait introduced into an organism/plant that gives that organism added value, like the addition of a valued trait or the capability to produce a new, valued substance, like a pharmaceutical or a biomaterial.

Vector: Agent, such as an insect, virus or plasmid, that is able to mechanically or biologically transfer itself or its contents from one organism to another. In genetic engineering this refers to any virus or plasmid into which a gene is introduced and which is subsequently transferred into a cell.

Virulence: Degree or severity of disease-causing potential of an organism.

Virus: Small genetic element, composed of either DNA or RNA that is protected by a protein coat. Virus is capable of existing either inside a cell (intracellular) or outside a cell (extracellular). Viruses cannot make copies of themselves without invading another cell and using some of its machinery.

Wild-type: Organism as discovered in nature.

Yeast: Kind of fungi or microbe. Yeast are used in bread-, wine- and beer-making to produce fermentation products.