Biotechnology and Genetics terms starting with P

399 terms

  1. petal One of the parts of the flower that make up the corolla.
  2. petiole Stalk of leaf. See: pedicel; peduncle.
  3. Petri dish Flat round glass or plastic dish with a matching lid, used for small-scale culturing of organisms, germinating seeds etc.
  4. PFGE Abbreviation for pulsed-field gel electrophoresis.
  5. PG One of several hormone-like substances made by the body. Different PGs control blood pressure, contraction of smooth muscles, and other processes within…
  6. pH A measurement for liquids to determine acidity or alkalinity. On a scale of one to 14, seven is considered neutral.
  7. pH-electrode-based sensor Sensor in which a standard pH electrode is coated with a biological material. Many biological processes raise or lower pH, and the changes can be detected…
  8. Phage Abbreviation for bacteriophage.
  9. Phage (particle) See Bacteriophage.
  10. phagemids Cloning vectors that contain components derived from both phage and plasmid DNA.
  11. phagocytes Immune system cells that ingest and destroy viruses, bacteria, fungi and other foreign substances or cells.
  12. phagocytosis (FA-goh-sy-TOH-sis) The process by which a phagocyte (a type of white blood cell) surrounds and destroys foreign substances (such as bacteria) and removes…
  13. pharmaceutical agent See: therapeutic agent.
  14. Pharmacogenomics The study of the interaction of an individual's genetic makeup and response to a drug.
  15. pharmacokinetics (FAR-muh-koh-kih-NEH-tix) The activity of drugs in the body over a period of time, including the processes by which drugs are absorbed, distributed in the…
  16. Phase Change A method of storing information on rewritable optical discs.
  17. phase state The coupling or repulsion of two linked genes.
  18. PHB Abbreviation for polyhydroxybutyrate.
  19. Phenocopy An environmentally induced, non hereditary variation in an organism, resembling a genetically determined trait.
  20. phenolic oxidation Common aspect of the wound response in plants. Phenolic oxidation is often indicated by blackening of tissue and it may be a precursor to growth…
  21. phenolics Compounds with hydroxyl group(s) attached to the benzene ring, forming esters, ethers and salts.
  22. Phenotype The observable characteristics of an organism, the expression of gene alleles (genotype) as an observable physical or biochemical trait. See Genotype.
  23. Phenotypic characteristics The genetically and environmentally determined physical characteristics of an organism.
  24. Pheromone A hormone-like substance that is secreted into the environment.
  25. phloem Specialized vascular plant tissue for the transport of assimilates (generally sugars) from the point of synthesis (in the leaf) to other parts of the…
  26. Phosphatase An enzyme that hydrolyzes esters of phosphoric acid, removing a phosphate group.
  27. phosphodiester (phospho-diester) bond A bond in which a phosphate group joins adjacent carbons through ester linkages.
  28. Phosphodiester bond A bond in which a phosphate group joins adjacent carbons through ester linkages.
  29. phospholipase A2 An enzyme which degrades type A2 phospholipids.
  30. phospholipid A lipid (fat) that contains phosphorus. Phospholipids are a major part of cell membranes.
  31. phosphorolysis The cleavage of a bond by orthophosphate; analogous to hydrolysis referring to cleavage by water.
  32. Phosphorylation The addition of a phosphate group to a compound.
  33. photo-bioreactor Bioreactor dependent on sunlight, which is taken up by its content of plant material, usually algae.
  34. photoautotroph See:.
  35. photoheterotroph See: heterotroph.
  36. photoperiod The length of daylight or period of daily illumination provided for growth.
  37. photoperiodism The photoperiod required by a plant to switch from the vegetative to the reproductive stage.
  38. photophosphorylation The formation of ATP from ADP and inorganic phosphate using light energy harvested by photosynthesis.
  39. photoreactivation A light dependent DNA repair process.
  40. photosynthate The carbohydrates and other compounds produced in photosynthesis.
  41. Photosynthesis A chemical process by which green plants synthesize organic compounds from carbon dioxide and water in the presence of sunlight.
  42. photosynthetic Able to use sunlight energy to convert atmospheric carbon dioxide into organic compounds.
  43. photosynthetic efficiency Efficiency of converting light energy into organic compounds.
  44. photosynthetic photon flux (Abbreviation: PPF). A measure of the intensity of light utilized by plants for photosynthetic activity.
  45. photosynthetically active radiation (Abbreviation: PAR). The part of the radiant energy that is capturable by natural photosynthetic systems (approximately equivalent to the natural light…
  46. phototropism The tendency of plants to direct shoot growth towards the source of light.
  47. phylogeny The deduced evolutionary history of related organisms.
  48. Physical map A map showing physical locations on a DNA molecule, such as restriction sites, and sequence-tagged sites. (See Mapping.)
  49. phyto- (Prefix) To do with plants.
  50. phytochemical (FY-toh-KEH-mih-kuhl) A substance found in plants. Some phytochemicals may reduce the risk of cancer.
  51. phytochrome A pigment, found in the cytoplasm of green plants, which can exist in two forms Pr (biologically inactive) and Pfr (biologically active).
  52. phytohormone A substance that stimulates growth or other processes in plants. Major species are auxin s, abscisic acid, cytokinin s, gibberellin s and ethylene.
  53. phytokinin See: cytokinin.
  54. phytoparasite Parasite on plants.
  55. phytoparasitic (adj.) See: phytoparasite.
  56. phytopathogen A plant pathogen.
  57. phytoremediation The use of plants actively to remove contaminants or pollutants from either soils (e.g. polluted fields) or water resources (e.g. polluted lakes).
  58. phytosanitary Plant health, including quarantine.
  59. phytostat Apparatus designed for the semi-continuous chemostatic culture of plant cells.
  60. phytosterol A plant-based compound that can compete with dietary cholesterol to be absorbed by the intestines, resulting in lower blood cholesterol levels.
  61. pigment A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.
  62. pinocytosis The engulfing of a minute droplet of liquid by a living cell.
  63. pipette Widely used device for accurate dispensing of small volumes of liquids.
  64. pistil Central organ of the flower, typically consisting of ovary, style and stigma. Usually referred to as the female part of a perfect flower.
  65. Placenta The organ that nourishes the developing fetus in the uterus.
  66. plant breeders' rights (Abbreviation: PBR). Legal protection of a new plant variety granted to the breeder or his successor in title.
  67. plant cell culture In vitro growth of plant cells.
  68. plant cell immobilization Entrapment of plant cells in gel matrices so that they are protected from physical damage.
  69. plant genetic resources (Abbreviation: PGR). The reproductive or vegetative propagating material of: 1.
  70. plant growth regulator An organic compound, either natural or synthetic, and other than a nutrient, that modifies or controls one or more specific physiological processes within…
  71. plant hormone See: plant growth regulator.
  72. Plant Pest Act (PPA) See U.S. Department of Agriculture.
  73. Plant Variety Act (PVA) See U.S. Department of Agriculture.
  74. plant variety protection (Abbreviation: PVP). Synonym for plant breeders' rights.
  75. plant variety rights See: plant breeders' rights.
  76. Plant-incorporated protectants Formerly referred to as plant-pesticides, plant-incorporated protectants (PIPs) are substances that act like pesticides produced and used by a plant to…
  77. plantibody An antibody expressed transgenically in an engineered plant.
  78. plantlet A small rooted shoot regenerated from cell culture following embryogenesis or organogenesis.
  79. plaque A film of mucus that traps bacteria on the surface of the teeth. Plaque can be removed with daily brushing and flossing of teeth.
  80. Plasma (PLAZ-muh) The clear, yellowish, fluid part of the blood that carries the blood cells. The proteins that form blood clots are in plasma.
  81. plasma cells Antibody-producing white blood cells derived from B lymphocyte s.
  82. plasma membrane (PLAZ-muh MEM-brayn) The outer membrane of a cell.
  83. plasmalemma The lipid bilayer and associated proteins and other molecules that surrounding the protoplast, within the cell wall.
  84. Plasmid An circular self-replicating non-chromosomal DNA molecule found in many bacteria, capable of transfer between bacterial cells of the same species, and…
  85. Plasmid (p) A circular DNA molecule, capable of autonomous replication, which typically carries one or more genes encoding antibiotic resistance proteins.
  86. plasmodesma (pl.: plasmodesmata) Fine protoplasmic thread that connects adjacent plant cells by passing through the plant cell wall.
  87. plasmolysis Shrinkage of protoplasm caused by removal of water from a cell through osmosis when surrounded by a hypertonic solution.
  88. Plasticity A phenomenon used to describe a cell that is capable of becoming a specialized cell type of different tissue.
  89. plastid A general term for a number of plant s which carry non-nuclear DNA. Includes the pigment -carrying bodies: 1. chloroplasts in leaves, 2.
  90. plastoquinone One of a group of compounds involved in the transport of electrons as part of the process of photosynthesis.
  91. plate 1. Verb: to distribute a thin film of micro-organisms or plant cells onto a solid medium. 2. Noun: refers to the two segments of a Petri dish or similar.
  92. Platelets Small, irregularly-shaped bodies in the blood that contain granules. These cells are important components of the blood coagulation (clotting) system.
  93. platform shaker See: shaker.
  94. plating efficiency The percentage of inoculated cells which give rise to cell colonies when seeded into culture vessels.
  95. Pleiotrophy The effect of a particular gene on several different traits.
  96. pleiotropic (adj.) See: pleiotropy.
  97. Pleiotropy The simultaneous effect of a given gene on more than one apparently unrelated trait.
  98. ploidy (PLOY-dee) The number of sets of chromosomes in a cell or an organism. For example, haploid means one set and diploid means two sets.
  99. plumule The first bud of an embryo, or that portion of the young shoot above the cotyledon s.
  100. Pluripotency The potential of a cell to develop into more than one type of mature cell, depending on environment.