CrownThe base of the stem of cereals and forage species from which tillers or branches arise. In woody plants, the root-stem junction.
crown gallA tumorous growth at the base of certain plants characteristic of infection by Agrobacterium tumefaciens.
CRPAbbreviation for catabolite regulator protein. See: catabolite activator protein.
cry proteinsA class of crystalline proteins produced by strains of Bacillus thuringiensis, and engineered into crop plants to give resistance against insect pests.
Cry1AA protein derived from the bacterium Bacillus thuringiensis that is toxic to some insects when ingested.
cryobiological preservationThe preservation of germplasm resources in a dormant state by storage at ultra-low temperatures, often in liquid nitrogen.
cryopreservationThe process of cooling and storing cells, tissues, or organs at very low or freezing temperatures to save them for future use.
Cryopreserved embryosEmbryos, generally those produced by in vitro fertilization exceeding the number that can be transferred for uterine implantation, that have been frozen.
cryoprotectantCompound preventing cell damage during successive freezing and thawing processes. Cryoprotectants are agents with high water solubility and low toxicity.
crypticAnything hidden. 1. Structurally heterozygous individuals that are not identifiable as they do not show abnormal meiotic chromosome pairing configurations…
CTPAbbreviation for 1. cytidine 5'-triphosphate, which is required for RNA synthesis since it is a direct precursor molecule; 2. Chloroplast transit peptide.
cultigenA cultivated plant species with no known wild progenitor.
Cultivar(Abbreviation: cv). An inteRNA tionally accepted term denoting a variety of a cultivated plant.
Culture(KUL-chur) The beliefs, values, and behaviors that are shared within a group, such as a religious group or a nation.
culture alterationA term used to indicate a persistent change in the properties of a culture's behaviour (e.g.
Culture mediumAny nutrient system for the cultivation of cells, bacteria or other organisms; usually a complex mixture of organic and inorganic nutrients.
culture roomA dedicated room for maintaining cultures, often in a controlled environment.
curingThe elimination of a plasmid from its host cell. Many agents which interfere with DNA replication, e.g.
cuticleLayer of cutin or wax, formed on the outer surface of leaves and fruits, thought to have evolved to reduce evaporative water loss.
CuttingA detached plant part that, with appropriate treatment, can regenerate into a complete plant.
cybridA hybrid, originating from the fusion of a cytoplast (the cytoplasm without nucleus) with a whole cell derived from a different species.
cyclic adenosine monophosphate(Abbreviations: cyclic AMP, cAMP). A "messenger" molecule that regulates many intracellular reactions by transducing signals from extracellular growth…
cyclic AMPAbbreviation for cyclic adenosine monophosphate.
Cyclic AMP (cyclic adenosine monophosphate)A second messenger that regulates many intracellular reactions by transducing signals from extracellular growth factors to cellular metabolic pathways.
Cyclin-dependent kinase (Cdk protein)Protein kinase that has to be complexed with a cyclin protein in order to act; different Cdk-cyclin complexes are thought to trigger different steps in…
DAB(Full term: single domain antibody ). Antibodies with only one (instead of two) protein chain derived from only one of the two domains of the normal…
DaltonA unit of measurement equal to the mass of a hydrogen atom, 1.67 x 10E-24 gram/L (Avogadro's number).
DAMDSee: directed amplification of minisatellite DNA.
Darwinian cloningSelection of a clone from a large number of essentially random starting points, rather than isolating a natural gene or making a carefully designed…
Data warehouseA collection of databases, data tables, and mechanisms to access the data on a single subject.
dATPAbbreviation for deoxyadenosine 5'-triphosphate. dATP is required for DNA synthesis since it is a direct precursor molecule. See: adenosine, adenylic acid.
dCTPAbbreviation for deoxycytidine 5'-triphosphate. dCTP is required for DNA synthesis since it is a direct precursor molecule. See: cytidine, cytidylic acid.
de-differentiationThe process, in response to wounding and in tissue cultures, by which plant cells can become unspecialized and start to proliferate by cell division to…
de-ionized waterWater from which most salts have been removed - with varying degrees of efficiency - by ion exchange.
Death phaseThe final growth phase, during which nutrients have been depleted and cell number decreases. (See Growth phase).
deceleration phaseThe phase of declining growth rate, following the linear phase and preceding the stationary phase in most batch-suspension cultures. See: growth phase.
Decidual cellsA cellular matrix that first surrounds an implanted embryo and later occupies most of the endometrium.
defective virusA virus that, by itself, is unable to reproduce when infecting its host cell, but that can grow in the presence of another virus.
deficiency(dih-FIH-shun-see) In medicine, a shortage of a substance (such as a vitamin or mineral) needed by the body.
defined1. Fixed conditions of medium, environment and protocol for growth. 2. Precisely known and stated elements of a tissue culture medium.
degeneracyThe specification of one amino acid by more than one codon. It arises from the inevitable redundancy resulting from the 64 possible codons encoding only…
degeneration1. Changes in cells, tissues or organs due to disease. 2. The reduction in size or complete loss of organs during evolution.
dehalogenationThe removal of halogen atoms (fluorine, chlorine, bromine, iodine) from molecules, for example during biodegradation.
dehiscenceThe spontaneous and often violent opening of a fruit, seed pod or anther to release and disperse the seeds or pollen.
dehydrogenaseAn enzyme that catalyses the removal of hydrogen atoms in biological reactions.
dehydrogenationA chemical reaction in which hydrogen is removed from a compound.
DeletionDeletion is the process whereby data is removed from active files and other data storage structures on computers and rendered inaccessible except using…
Deletion mapA description of a specific chromosome that uses defined mutations --specific deleted areas in the genome-- as 'biochemical signposts,' or markers for…
deliberate releaseIn a biotechnology context, the intentional release of genetically modified organisms.
demineralizeTo remove the mineral content (salts, ions) from a substance, especially water. Removal methods include distillation, electrodialysis and ion exchange.
DenatureTo induce structural alterations that disrupt the biological activity of a molecule.
denatured DNADouble-stranded DNA that has been converted to single strands by breaking the hydrogen bonds linking complementary nucleotide pairs. Often reversible.
denatured proteinAltering the in vivo conformation of a protein by heat or salt treatment, thereby destroying its biological activity.
denaturing gradient gel electrophoresis(Abbreviation: DGGE ). An electrophoresis method for separating similar sized DNA fragments on the basis of their sequence, by applying across the gel a…
dendrimerA polymer that repeatedly branches until stopped by the physical constraint of having formed a complete, hollow sphere.
DendriteExtension of a nerve cell, typically branched and relatively short, that receives stimuli from other nerve cells.
denitrificationA chemical process in which nitrates in the soil are reduced to molecular nitrogen, which is released to the atmosphere.
Density gradient centrifugationHigh-speed centrifugation in which molecules "float" at a point where their density equals that in a gradient of cesium chloride or sucrose.
Dental pulpThe soft part inside a tooth, containing blood vessels and nerves.