المصطلحات العلمية GLOSSARY

 

q  Agrobacterium -   a natural bacterium that can be used to transfer DNA genes into broadleaf plants, such as tobacco, tomato, or soybean. q  Chromosome - a cellular structure comprised of a long, folded DNA molecule and protein. q  DNA - deoxyribonucleic acid, the substance within cells that carries the "recipe" for the organism and is inherited by offspring from parents. q  DNA fingerprinting -   cutting a DNA chromosome with restriction enzymes and separating the pieces by electrophoresis to generate a unique pattern, the "fingerprint" for each species, breed, hybrid, or individual, depending on which enzymes and probes are use d. q  Electrophoresis - a lab technique for determining DNA fragment sizes by separating them in a gel placed in an electric field. q  Electroporation - using an electric shock to transfer DNA into the cells of an organism; one of several procedures called transformation. q  Gene -   a functional unit of DNA, one "word" in the DNA recipe. q  Genetic code - the information contained in DNA molecules that scientists describe on the basis of a 4-letter alphabet (A, C, G, and T). q  Genetic engineering - the process of transferring DNA from one organism into another that results in a genetic modification; the production of a transgenic organism. q  Genetic map - the locations of specific genes along a chromosome marked with probes. q  Genome - the entire DNA "recipe" for an organism, found in every cell of that organism. q  Mutation - a change of one of the "letters" in the DNA "recipe" caused by chemicals, ultraviolet light, X-rays, or natural processes. q  Particle gun - a gun that shoots DNA into the cells of an organism; the most versatile of a series of procedures called transformation. q  PCR - polymerase chain reaction, which rapidly duplicates specific DNA molecules in response to temperature changes in a computer-controlled heater. q  Plasmid - a small, circular DNA that is used to transfer genes from one organism into another. q  Probe - a very short piece of DNA used to find a specific sequence of "letters" in a very long piece of DNA from a chromosome or genome. q  Recombinant DNA - DNA formed by joining pieces of DNA from two or more organisms. q  RFLP - restriction fragment length polymorphism, which describes the patterns of different (polymorphism) sizes of DNA (fragment length) that result from cutting with restriction enzymes (restriction). See DNA fingerprinting above. Sequence - the order of "letters" in the DNA "recipe." The DNA sequence is the chemical structure that contains information. q  Transformation - a procedure to transfer DNA into the cells of an organism. Can be done with Agrobacterium (most dicots), calcium chloride (bacteria), electroporation (any organism), or the particle gun (any organism). q  Transgenic - an organism that has been modified by genetic engineering to contain DNA from an external source. q  Vector - any DNA structure that is used to transfer DNA into an organism; most commonly used are plasmid DNA vectors or viruses.