Biotechnology and Genetics terms starting with T

196 terms

T Abbreviation for thymine.
T cell One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells.
T cell receptor An antigen -binding protein, located on the surface of mammalian killer T cells, which mediates the cellular immune response.
T cells A type of white blood cell that is of crucial importance to the immune system. Immature T cells migrate to the thymus gland in the upper chest cavity…
T lymphocyte One type of white blood cell that attacks virus-infected cells, foreign cells, and cancer cells.
T-cell-mediated (cellular) immune response The synthesis of antigen-specific T cell receptors and the development of killer T cells in response to an encounter of immune system cells with an…
T-DNA The DNA segment of the Ti plasmid, present in pathogenic Agrobacterium tumefaciens, that is transferred to plant cells and inserted into the plant's DNA…
T-DNA (transfer DNA, tumor-DNA) The transforming region of DNA in the Ti plasmid of Agrobacterium tumefaciens.
T0, T1 and T2 Successive generations of plants following a transformation event. The parent transformed plant is T0, its immediate progeny is T1, and the progeny of the…
T0, T1 and T2 cell .
T4 DNA ligase An enzyme, present in bacteria infected with bacteriophage T4, which catalyses the joining (ligation ) of, and repairs nicks in, duplex DNA molecules.
tag See: label.
tailing The in vitro addition, to the 3'-hydroxyl ends of a double-stranded DNA molecule, of multiple copies of a single nucleotide by the enzyme terminal…
tandem array See: tandem repeat.
tandem repeat Two (or more) contiguous identical DNA sequences. The orientation can be either head-to-tail, or head-to-head.
Tandem repeat sequences Multiple copies of the same base sequence on a chromosome; used as markers in physical mapping. See also: physical map
tank bioreactor A fermentation vessel designed to grow large scale quantities of a micro-organism (bacteria, yeast or fungi).
tap root Root system in which the primary root has a much larger diameter than any lateral roots (e.g. carrot). Opposite: fibrous root.
Taq polymerase A heat-stable DNA polymerase isolated from the bacterium Therrnus aquaticus, used in PCR. (See Polymerase.)
Target In diagnostic tests, the molecule or nucleic acid sequence assayed in a sample.
target site duplication A short sequence of DNA duplicated when a transposable element inserts at a new locus; usually found at each end of the insertion.
targeted drug delivery A method of delivering the activated form of a drug molecule to the site in the body where it is needed, rather than allowing it reach the target by…
Targeted mutagenesis Deliberate change in the genetic structure directed at a specific site on the chromosome. Used in research to determine the targeted region's function.
targeting vector A cloning vector carrying a DNA sequence capable of participating in a recombinational event at a specified chromosomal location in the host cell.
TATA box An adenine- and thymine-rich promoter sequence located 25-30 bp upstream of a gene, which is the binding site of RNA polymerase.
tautomeric shift The transfer of a hydrogen atom from one position in an organic molecule to another position.
tautomerism A type of isomerism in which the two isomers arising from a tautomeric shift are in equilibrium.
Technology transfer The process of providing the private sector access to technological advances developed by scientists in the Federal government. See also
Telomerase An enzyme that maintains the structure of the telomere by adding the required repetitive sequences to the ends of eukaryotic chromosomes.
Telomere The end of a chromosome.
telophase The last stage in each mitotic or meiotic division, in which the chromosomes coalesce at each pole of the dividing cell.
temperate phage A phage (virus ) that invades but does not normally destroy (lyse) the host bacterial cell.
temperature-sensitive mutant An organism that can grow at one temperature but not at another.
temperature-sensitive protein A protein that is functional at one temperature but loses function at another (usually higher) temperature.
Template a standard shape that the race car must comply to be within the NASCAR rules. The template closely resembles the shape of the factory car.
template strand See: anticoding strand.
Tenocyte Tendon-producing cell.
Teratocarcinoma (TAYR-uh-toh-KAR-sih-NOH-muh) A type of germ cell cancer that usually forms in the testes (testicles).
Teratogen A drug or other agent that raises the incidence of congenital malformations.
Teratogenic Substances such as chemicals or radiation that cause abnormal development of a embryo. See also: mutagen
Teratoma (tayr-uh-TOH-muh) A type of germ cell tumor that may contain several different types of tissue, such as hair, muscle, and bone.
terminal bud A branch tip, an undeveloped shoot containing rudimentary floral buds or leaves, enclosed within protective bud scales.
terminal transferase An enzyme that catalyses the addition of nucleotides to the 3' end of a DNA molecule.
terminalization Repelling movement of the centromeres of bivalents in the diplotene stage of the meiotic prophase, that appears to move visible chiasmata toward the ends…
Termination codon Any of three mRNA sequences (UGA, UAG, UAA) that do not code for an amino acid and thus signal the end of protein synthesis. Also known as stop codon.
termination signal In transcription, a nucleotide sequence that specifies RNA chain termination.
terminator 1. A DNA sequence just downstream of the coding segment of a gene, which is recognized by RNA polymerase as a signal to stop synthesizing mRNA. 2.
terminator codon See: stop codon.
terminator gene A specific variety-level genetic use restriction technology. A patented technique.
Terminator region A DNA sequence that signals the end of transcription.
tertiary structure The three-dimensional conformation taken up by complete macromolecules as a result of intramolecular interactions, such as hydrogen-bonding.
test-tube fertilization See: in vitro fertilization.
testcross A cross between a genetically unknown individual and a recessive tester to determine whether the individual in question is heterozygous or homozygous for…
testis (TES-tis) One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testicle.
testosterone (tes-TOS-ter-own) A hormone that promotes the development and maintenance of male sex characteristics.
Tetracycline An antibiotic drug used to treat infection.
tetrad The four haploid cells formed after the second meiotic division in plants (pollen tetrads) or fungi (ascospores).
tetraploid An organism, or a tissue whose cells contain four haploid sets of chromosome s.
tetrasomic (Noun: tetrasome). Pertaining to a nucleus or an organism with four members of one of its chromosomes, whereas the remainder of its chromosome complement…
tetratype In fungi, a tetrad of spores that contains four different types; e.g. AB, aB, Ab and ab.
TGGE Abbreviation for thermal gel gradient electrophoresis.
thallus Plant body without true roots, stems, or leaves.
therapeutic agent A compound used for the treatment of a disease or for improving the well-being of an organism. Synonyms: pharmaceutical agent, drug.
Therapeutic cloning The potential use of stem cells to grow, in vitro, tissue or organs for use in transplantation.
thermal gel gradient electrophoresis (Abbreviation: TGGE). A method for separating DNA fragments according to their mobility under increasingly denaturing conditions imposed by heat.
thermal shock Exposure to reduced or increased temperature for a significant period.
thermolabile Not resistant to heat, often in the context of a molecule which is unstable upon heating. Opposite: thermostable.
thermophile An organism which is adapted to high temperatures, such as in hot springs and geysers, smoker vents on the sea floor, and domestic hot water pipes.
thermosensitivity Loss of biological activity of a molecule at high temperature.
thermostable A molecule which retains its biological activity at some specified higher temperature. Opposite: thermolabile.
thermotherapy (THER-moh-THAYR-uh-pee) Treatment of disease using heat.
Thiazolidinediones A class of antidiabetes drugs that enhances the activity of insulin.
thinning 1. Removal of older stems to promote new growth. 2. Removal of excess fruits to improve the size and quality of the remaining fruits. 3.
Thrombocyte (Platelet) A tiny, disc-shaped blood cell responsible for controlling abnormal or excessive bleeding.
Thrombopoietin (THROM-boh-POY-eh-tin) A substance made by the body that helps make blood cells, especially platelets.
thymidine A chemical compound found in DNA. Also used as treatment for mucositis.
thymidine kinase (Abbreviation: tk). An enzyme that allows a cell to utilize an alternate metabolic pathway for incorporating thymidine into DNA.
Thymidine kinase (tk) An enzyme that allows a cell to utilize an alternate metabolic pathway for incorporating thymidine into DNA.
thymidine triphosphate Abbreviation: TTP; dTTP is strictly correct but rarely used.
thymidylic acid (Abbreviation: TMP or dTMP). Synonym for thymidine 5'-monophosphate, a deoxyribonucleotide containing the nucleoside thymidine.
thymine (Abbreviation: T). One the bases found in DNA. See: thymidine.
Thymine (T) A nitrogenous base, one member of the base pair AT (adenine-thymine). See also: base pair, nucleotide
Thymus An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.
Ti (tumor-inducing) plasmid A giant plasmid of Agrobac- terium tumefaciens that is responsible for tumor formation in infected plants.
Ti plasmid Tumour-inducing plasmid. A large plasmid present in pathogenic Agrobacterium tumefaciens, responsible for the induction of tumours in plant with crown…
Tissue (TISH-oo) A group or layer of cells that work together to perform a specific function.
Tissue culture The in vitro culture of cell s, tissue s or organ s in a nutrient medium under sterile conditions.
titre 1. The concentration of infectious virus particles present in a suspension. 2. A measure of antibody concentration, given by the highest dilution of the…
tk Abbreviation for thymidine kinase.
TMP Abbreviation for the deoxyribonucleotide thymidine 5'-monophosphate. See: thymidylic acid.
Tolerance A condition in which higher doses of a drug are required to produce the same effect achieved during initial use; often associated with physical dependence.
Tolerance induction The "education" process that T cells undergo to discriminate between self and foreign proteins. This process takes place primarily in the thymus.
tonoplast The cytoplasmic membrane bordering the vacuole of plant cells. It plays a prominent role in regulating the osmotic pressure exerted by the cell sap.
topo-isomerase See: DNA topo-isomerase.
Total Body Irradiation (TBI) Radiation given to the entire body.
totipotency The ability of a cell or tissue to be induced to regenerate into a complete organism.
Totipotent Having to do with cells that are able to develop into any type of cell found in the body.
Totipotent stem cells Stem cells that can give rise to all cell types that are found in an embryo, fetus, or developed organism, including the embryonic components of the…
Toxic Substances Control Act (TSCA) The Toxic Substances Control Act (TSCA), passed in 1976, requires tests of chemicals that may harm human health or the environment; reviews of new…
toxicity (tok-SIH-sih-tee) The extent to which something is poisonous or harmful.