Biotechnology and Genetics terms starting with A

285 terms

antitranspirant A compound designed to reduce plant transpiration. Applied to the leaves of newly transplanted trees, shrubs etc., or cuttings in lieu of misting.
antixenosis The modification of the behaviour of an organism by a substance or another organism.
AP-PCR See: arbitrarily primed polymerase chain reaction.
APEX The portion of a root or shoot containing the primary or apical meristem.
Apheresis A procedure in which blood is collected, part of the blood such as platelets or white blood cells is taken out, and the rest of the blood is returned to…
apical cell A meristematic initial in the apical meristem of shoots or roots of plants.
apical dominance The phenomenon where growth of lateral (axillary) bud s in a plant is inhibited by the presence of the terminal (apical) bud on the branch.
apical meristem A region of the tip of each shoot and root of a plant in which cell division is continually occurring to produce new stem and root tissue, respectively.
apoenzyme Inactive enzyme that has to be associated with a co-enzyme in order to function. The apoenzyme/co-enzyme complex is called a holoenzyme.
apomixis The production of an embryo in the absence of meiosis. Apomictic higher plants produce asexual seeds, derived only from maternal tissue.
apoptosis (A-pop-TOH-sis) A type of cell death in which a series of molecular steps in a cell leads to its death.
aptamer A polynucleotide molecule that binds to a specific molecule, often a protein.
Aquaculture Farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants.
Arabidopsis A genus of flowering plants in the Cruciferae. A. thaliana is used in research as a model plant because it has a small fully sequenced genome, can be…
arbitrarily primed polymerase chain reaction (Abbreviation: AP-PCR) An application of the polymerase chain reaction to generate DNA fingerprints .
arbitrary primer An oligonucleotide primer whose sequence is chosen at random, rather than one whose sequence matches that of a known locus.
Archaea Single-celled life forms adapted to existence in high pressure, anaerobic, environments such as at extreme ocean depths.
ARMG Abbreviation for antibiotic resistance marker gene.
Arrayed library Individual primary recombinant clones (hosted in phage, cosmid, YAC, or other vector) that are placed in two-dimensional arrays in microtiter dishes.
ARS Abbreviation for autonomous(ly) replicating segment (or sequence).
artificial inembryonation Non-surgical transfer of embryo(s) to a recipient female. As in vitro embryo technology develops, artificial inembryonation may replace artificial…
artificial insemination (Abbreviation: AI). The deposition of semen, using a syringe, at the mouth of the uterus to make conception possible.
artificial medium See: culture medium.
artificial seed Encapsulated or coated somatic embryos that are planted and treated like seed.
artificial selection The practice of choosing individuals from a population for reproduction, usually because these individuals possess one or more desirable traits.
ASA Abbreviation for allele-specific amplification.
ascites (uh-SY-teez) Abnormal buildup of fluid in the abdomen that may cause swelling. In late-stage cancer, tumor cells may be found in the fluid in the abdomen.
ascospore One of the spores contained in the ascus of certain fungi.
ascus (pl.: asci) Reproductive sac in the sexual stage of a type of fungi (Ascomycetes) in which ascospores are produced.
aseptic Sterile, free of contaminating organisms (bacteria, fungi, algae but not generally including viruses, and particularly not internal symbionts ).
asexual Reproduction not involving meiosis or the union of gametes.
asexual embryogenesis See: somatic cell embryogenesis.
asexual propagation Vegetative, somatic, non-sexual reproduction of a plant without fertilization.
Asexual reproduction Nonsexual means of reproduction which can include grafting and budding.
assay (AS-say) A laboratory test to find and measure the amount of a specific substance.
Assembly Putting sequenced fragments of DNA into their correct chromosomal positions.
assortative mating Mating in which the partners are chosen on the basis of phenotypic similarity.
assortment See: segregation.
Astrocyte (AS-troh-site) A star-shaped cell that helps nerve cells in the brain and spinal cord work the way they should. An astrocyte is a type of glial cell.
asymmetric hybrid A hybrid formed, usually via protoplast fusion, between two donors, where the chromosome complement of one of the donors is incomplete.
asynapsis The failure or partial failure in the pairing of homologous chromosomes during the first meiotic prophase.
ataxia-telangiectasia A rare, inherited, progressive, degenerative disease of childhood that causes loss of muscle control, a weakened immune system, and an increased risk of…
ATP A substance present in all living cells that provides energy for many metabolic processes and is involved in making RNA.
ATP-ase An enzyme that brings about the hydrolysis of adenosine triphosphate, by the cleavage of either one phosphate groups with the formation of ADP and…
attenuated vaccine A virulent organism that has been modified to produce a less virulent form, but nevertheless retains the ability to elicit antibodies against the virulent…
Attenuation A mechanism for controlling gene expression in prokaryotes that involves premature termination of transcription.
attenuator A nucleotide sequence in the 5' region of a prokaryotic gene (or in its RNA ) that causes premature termination of transcription, possibly by forming a…
aureofacin An antifungal antibiotic produced by a strain of Streptomyces aureofaciens. A possible candidate for the transgenic control of plant fungal disease.
authentic protein A recombinant protein that has all the properties - including any post-translational modifications - of its naturally occurring counterpart.
auto-immune disease Disorder in which the immune systems of affected individuals produce antibodies against molecules that are normally produced by those individuals (called…
auto-immunity A disorder in the body's defence mechanism in which an immune response is elicited against its own (self) tissues.
Autoantibody An antibody that reacts with antigens found on the cells and tissues of an individual's ownbody. Autoantibodies can cause autoimmune diseases.
autocatalysis Catalysis in which one of the products of the reaction is a catalyst for the reaction.
autocatalytic reaction See: autocatalysis.
autoclave (AW-toh-KLAYV) A device that uses steam under high pressure to sterilize medical and laboratory supplies and equipment.
autogenous control The action of a gene product to inhibit (negative autogenous control) or enhance (positive autogenous control) the expression of the gene that codes for…
Autoimmune disease (AW-toh-ih-MYOON...) A condition in which the body recognizes its own tissues as foreign and directs an immune response against them.
Autoimmune Lymphoproliferative syndrome (ALPS) A human disease caused by failure of lymphocytes to die once they have finished doing their job.
Autologous (aw-TAH-luh-gus) Taken from an individual's own tissues, cells, or DNA.
autologous cells Cells taken from an individual, cultured (or stored), and, possibly, genetically manipulated before being transferred back into the original donor.
Autologous Stem Cell Transplant A transplant involving the infusion of a patient's own bone marrow or stem cells to produce new, healthy marrow.
Autologous transplant Cell, tissue or organ transplants from one individual back to the same individual. Such transplants do not induce an immune response and are not rejected.
autolysis The process of self destruction of a cell, cell organelle, or tissue, through the action of lysosomic enzymes.
autonomous A term applied to any biological unit that can function on its own, i.e. without the help of another unit, such as a transposable element that encodes an…
autonomous(ly) replicating segment (or sequence) (Abbreviation: ARS). Any eukaryotic DNA sequence that initiates and supports chromosomal replication; they have been isolated in yeast cells.
autopolyploid A polyploid whose constituent genomes are derived from the same or nearly the same progenitor.
autoradiograph A technique for visualizing the presence, location and intensity of radioactivity in histological preparations, paper chromatograms or electrophoretic gel…
Autoradiography A technique that uses X-ray film to visualize radioactively labeled molecules or fragments of molecules; used in analyzing length and number of DNA…
Autosomal dominant A pattern of Mendelian inheritance whereby an affected individual possesses one copy of a mutant allele and one normal allele.
Autosome A chromosome that is not involved in sex determination.
autotroph Organism capable of self-nourishment utilizing carbon dioxide or carbonates as the sole source of carbon and obtaining energy from radiant energy or from…
autotrophic (adj.) See: autotroph.
auxin A group of plant growth regulators (natural or synthetic) which stimulate cell division, enlargement, apical dominance, root initiation, and flowering.
auxin-cytokinin ratio The relative proportion of auxin to cytokinin present in plant tissue culture media.
auxotroph A mutant cell or micro-organism lacking one metabolic pathway present in the parental strain, and that consequently will not multiply on a minimal medium…
Availability A reflection of the form and location of nutritional elements and their suitability for absorption.
avidin A glycoprotein present in egg white, which has a strong affinity to biotin. Can lead to biotin deficiency if given in large quantities.
avidity A measure of the binding strength of an antibody to its antigen.
avirulence gene (Abbreviation: avr gene). Many plants contain R genes, which confer simply-inherited resistance to a specific pathogen race.
avr gene Abbreviation for avirulence gene.
Avuncular relationship The genetic relationship between nieces and nephews and their aunts and uncles.
axenic culture Free of external contaminants and internal symbionts; generally not possible with surface sterilization alone, sometimes used incorrectly to indicate.
axillary bud A bud found at the axil of a leaf. Synonym: lateral bud.
axillary bud proliferation Propagation of plant tissue in vitro to promote axillary growth, to generate large numbers of plantlets in culture.
Axis A straight line passing through a spherical body between its two poles. The central line of the body or any of its parts. The vertebral column.