Biotechnology and Genetics — page 31 of 40

3,925 terms including subtopics (0 terms filed directly here)

Subtopics

Biotechnology and Genetics terms

  1. protocol An action plan for a clinical trial. The plan states what the study will do, how, and why.
  2. protocorm A tuberous structure, formed following the germination of orchid seeds, from which develops a complete plant.
  3. protoderm A primary that gives rise to epidermis.
  4. protogyny The condition in which the female reproductive organs (carpel s) of a flower mature before the male ones (stamen s), thereby ensuring that…
  5. protomeristem See: pro-meristem.
  6. protoplasm The essential, complex living substance of cells, upon which all vital functions of nutrition, secretion, growth and reproduction depend.
  7. protoplast A bacterial or plant cell for which the cell wall has been removed either chemically or enzymatically, leaving its cytoplasm enveloped by a peripheral…
  8. protoplast culture The culturing in vitro of plant protoplast s. Where protoplasts can be regenerated into whole plants, they represent an attractive target for genetic…
  9. protoplast fusion The induced or spontaneous coalescence of two or more protoplast s of the same or different species origin.
  10. prototroph A nutritionally independent cell. Opposite: auxotroph.
  11. Protozoan Single-celled organism that can perform all necessary functions of metabolism and reproduction.
  12. protruding end See: extension.
  13. provenance The geographical and/or genetic origin of an individual.
  14. Provirus See virus.
  15. pseudo-affinity chromatography A chromatographic technique in which a ligand is immobilized selectively to retain enzymes or other protein s.
  16. pseudo-autosomal region A section at one end of the X and Y chromosomes for which there is sufficient homology that there is synapsis between them during meiosis.
  17. pseudocarp A fruit that incorporates, in addition to the ovary wall, other parts of the flower, such as the receptacle (e.g. strawberry). Synonym: false fruit.
  18. pseudogene An incomplete or mutated copy of a gene which is not transcribed because it lacks a continuous open reading frame.
  19. Pseudomonas spp. A widely distributed Gram-negative bacterial genus. Many of the soil forms produce a pigment that fluoresces under ultraviolet light, hence the…
  20. psychrophile A micro-organism that can grow at temperatures below 30 °C and as low as 0 °C. See: mesophile, thermophile.
  21. Public Health Service Act See Food and Drug Administration.
  22. PUC A widely used expression plasmid containing a -galactosidase gene. (See Plasmid.)
  23. pulsed-field gel electrophoresis (Abbreviation: PFGE). A procedure used to separate very large (50 kbp to several Mbp) DNA molecules by alteRNA ting the direction of electric current in a…
  24. punctuated equilibrium The occurrence of speciation events in bursts, separated by long intervals of species stability.
  25. pure line A strain in which all members are genetically nearly identical and are indistinguishable by phenotype.
  26. purification tag See: affinity tag.
  27. Purine A double-ring, nitrogen-containing base present in nucleic acids . Adenine (A) and guanine (G) are the two purines normally present in DNA and RNA…
  28. PVA The Plant Variety Act. See U.S. Department of Agriculture.
  29. PvP Player vs. Player. This means for one player to attack another player.
  30. PVR Abbreviation for plant variety rights.
  31. PWP Abbreviation for permanent wilting point.
  32. pyrethrins Active constituents of pyrethrum (Tanacetum cinerariifolium) flowers, used as insecticides.
  33. Pyrimidine A single-ring, nitrogen-containing base present in nucleic acid s. Cytosine (C) and thymine (T) are present in DNA, whereas uracil (U) replaces T in RNA.
  34. pyrogen Bacterial substance that causes fever in mammals.
  35. pyrophosphate A phosphate ion dimer; may be released on hydrolysis of ATP.
  36. Q Denotes the longer of the two chromosome arms, e.g. human 10q is the long arm of human chromosome 10.
  37. q-beta replicase A viral RNA polymerase secreted by a bacteriophage that infects E. coli. It has the property of being able to copy RNA sequences at a rapid rate.
  38. QSAR Abbreviation for quantitative structure-activity relationship.
  39. QTL Abbreviation for quantitative trait locus.
  40. quadrivalent A chromosome configuration visible in late prophase and metaphase of the first meiotic division, where four chromosome s are linked by chiasmata.
  41. quadruplex The inheritance of alleles in autotetraploids. A genotype AAAa will produce gametes AA, Aa in the ratio 3:1.
  42. qualitative trait A trait that shows discontinuous variation - i.e. individuals can be assigned to one of a small number of discrete classes.
  43. quantitative genetics The area of genetics concerned with the inheritance of quantitative traits that show continuous variation, as opposed to qualitative trait s.
  44. quantitative inheritance Inheritance of measurable traits that depend on the cumulative action of many genes and/or involve a significant proportion of non-genetic determination.
  45. quantitative structure-activity relationship (Abbreviation QSAR). A computer modelling technique that enables the prediction of the likely activity of a molecule before it is synthesized.
  46. quantitative trait A measurable trait that shows continuous variation (e.g. height, weight, colour intensity, etc.) - i.e.
  47. quantitative trait locus (Abbreviation: QTL). A locus where is associated with variation in a quantitative trait.
  48. quantum speciation The rapid formation of new species, primarily by genetic drift.
  49. quarantine Isolation for a period after arrival in a new location, to allow any pre-existing disease symptoms to appear.
  50. quaternary structure A level of protein structure where several individual molecules assemble together and form a functional cluster.
  51. quiescent A temporary suspension or reduction in the rate of activity or growth, while retaining the potential to resume prior activity.
  52. R genes A class of plant genes conferring resistance to a specific strain (or group of strains) of a particular pathogen.
  53. R-loops Single-stranded DNA regions in RNA -DNA hybrids formed in vitro under conditions where RNA -DNA duplexes are more stable than DNA -DNA duplexes.
  54. R1 The first-generation offspring of a recombinant (genetically modified) organism. Not standard terminology. See: T0, T1, and T2.
  55. RACE A distinguishable group of organisms of a particular species. Criteria for distinctness can be one or a combination of geographic, ecological…
  56. raceme An inflorescence in which the main axis is elongated but the flowers are borne on pedicels that are about equal in length.
  57. rachilla Shortened axis of a spikelet.
  58. rachis Main axis of a spike; axis of fern leaf (frond) from which pinnae arise; in compound leaves, the extension of the petiole corresponding to the midrib of…
  59. Radiation hybrid A hybrid cell containing small fragments of irradiated human chromosomes. Maps of irradiation sites on chromosomes for the human, rat, mouse, and other…
  60. radiation hybrid cell panel (Abbreviation: RH). A somatic cell hybrid panel in which the chromosomes from the species of interest have been fragmented by irradiation prior to cell…
  61. Radiation Oncologist (RAY-dee-AY-shun on-KAH-loh-jist) A doctor who specializes in using radiation to treat cancer.
  62. radicle The portion of the plant embryo which develops into the primary root.
  63. Radioimmunoassay (Abbreviation: RIA). An assay based on the use of a radioactively labelled antibody, where the amount of radiation detected indicates the amount of target…
  64. radioisotope (RAY-dee-oh-I-suh-tope) An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable.
  65. raft culture See: nurse culture.
  66. ramet An individual member of a clone, descended from the ortet.
  67. random amplified polymorphic DNA (Abbreviation: RAPD). A PCR -based genotyping technique in which genomic template is amplified with single, short (usually 10-mer) randomly chosen primers.
  68. random genetic drift See: genetic drift.
  69. random mutagenesis A non-directed change of one or more nucleotide pairs in a DNA molecule.
  70. random primer method A method for labelling DNA probes, mainly for Southern hybridization experiments.
  71. RAPD Abbreviation for random amplified polymorphic DNA.
  72. Rare-cutter enzyme See: restriction-enzyme cutting site
  73. rate-limiting enzyme The enzyme whose activity controls the output of final product from a multi-enzyme metabolic pathway.
  74. rational drug design A systematic method of creating compounds by analysing their structure, function and stereochemical interactions.
  75. read-through Transcription or translation that proceeds beyond the normal stopping point because of the absence of the usual transcription or translation termination…
  76. Reading frame A series of triplet codons beginning from a specific nucleotide. Depending on where one begins, each DNA strand contains three different reading frames.
  77. recA A protein, found in most bacteria, that is essential for DNA repair and DNA recombination.
  78. recalcitrant Of seeds, unable to survive drying and subsequent storage at low temperature. See: field gene bank.
  79. receptacle Enlarged end of the pedicel or peduncle, to which other flower parts are attached.
  80. receptor (reh-SEP-ter) A molecule inside or on the surface of a cell that binds to a specific substance and causes a specific physiologic effect in the cell.
  81. receptor-binding screening A biotechnology-based method for drug discovery, which relies on the fact that many drugs act by binding to specific receptors on or in cells.
  82. recessive Describing an allele whose effect with respect to a particular trait is not evident in heterozygotes. Opposite: dominant.
  83. recessive allele Allelic state of a gene, where homozygosity is required for the expression of the relevant phenotype. Opposite:.
  84. Recessive gene Characterized as having a phenotype expressed only when both copies of the gene are mutated or missing.
  85. recessive oncogene A single copy of this gene is sufficient to suppress cell proliferation; the loss of both copies of the gene contributes to cancer formation.
  86. Recessive(-acting) oncogene, (anti-oncogene) A single copy of this gene is sufficient to suppress cell proliferation; the loss of both copies of the gene contributes to cancer formation.
  87. recessive-acting oncogene See: recessive oncogene.
  88. Reciprocal translocation When a pair of chromosomes exchange exactly the same length and area of DNA. Results in a shuffling of genes.
  89. reciprocating shaker A platform shaker used for agitating culture flasks, with a back and forth action at variable speeds.
  90. recognition sequence Synonym of recognition site.
  91. Recognition sequence (site) A nucleotide sequence--composed typically of 4, 6, or 8 nucleotides--that is recognized by a restriction endonuclease.
  92. recognition site A nucleotide sequence, typically 4-8bp long and often palindromic, that is recognized by, and at which a restriction endonuclease binds to the DNA.
  93. recombinant (ree-KOM-bih-nunt) In genetics, describes DNA, proteins, cells, or organisms that are made by combining genetic material from two different sources.
  94. Recombinant clone Clone containing recombinant DNA molecules. See also: recombinant DNA technology
  95. recombinant DNA The process of cutting and recombining DNA fragments from different sources as a means to isolate genes or to alter their structure and function.
  96. Recombinant DNA molecules A combination of DNA molecules of different origin that are joined using recombinant DNA technologies.
  97. Recombinant DNA molecules (rDNA) A combination of DNA molecules of different origin that are joined using recombinant DNA technologies.
  98. Recombinant DNA technology A set of techniques for manipulating DNA, including: the identification and cloning of genes; the study of the expression of cloned genes; and the…
  99. recombinant human (Abbreviation rh). A prefix denoting molecules made through the use of recombinant DNA technology.
  100. recombinant protein A protein encoded by a cloned gene. Synonym: heterologous protein.