Biotechnology and Genetics — page 27 of 40

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

Subtopics

Biotechnology and Genetics terms

  1. organism A living thing, such as an animal, a plant, a bacterium, or a fungus.
  2. organized growth The development under tissue culture conditions of organized explants (meristem tips or shoot tips, floral buds or organ primordia).
  3. organized tissue Composed of normally differentiated cells.
  4. organogenesis The initiation of adventitious or de novo shoots or roots from callus, meristem or suspension cultures. See: micropropagation; regeneration.
  5. organoid An organ-like structure produced in culture.
  6. organoleptic Having an effect on one of the organs of sense, such as taste or smell.
  7. Origin of replication The nucleotide sequence at which DNA synthesis is initiated.
  8. orphan gene A gene or DNA sequence whose function is not known.
  9. orphan receptor A receptor for which a cellular function or ligand has yet to be identified.
  10. ortet The plant from which a clone is obtained. Synonym: donor plant.
  11. orthologous Homologous genes/gene products that have evolved divergently between species; many rice genes have orthologues in other cereal genomes, because of the…
  12. OSHA See Occupational Safety and Health Administration.
  13. osmosis Diffusion of water across a semi-permeable membrane from zones of low solute concentration to zones of higher solute concentration.
  14. osmotic potential Change in the energy state of solvent brought about by dissolving a substance in the solvent - water in the biological sciences.
  15. osmoticum A chemical agent (e.g. polyethylene glycol, mannitol, glucose or sucrose) employed to maintain the osmotic potential of a nutrient medium equivalent to…
  16. Osteocalcin (OC) A cytokine produced by osteoblasts that promotes bone formation.
  17. Osteoclast A giant multi-nuclear cell formed in the bone marrow of growing bones.
  18. Osteocyte A cell from the bone tissue.
  19. Osteogenesis imperfecta A large and miscellaneous group of conditions of abnormal fragility and plasticity of bone, with recurring fractures on trivial trauma.
  20. Osteoprogenitor A cell-type that differentiates into a mature osteocyte.
  21. outbreeding A mating system characterized by the inter-breeding of genetically unrelated or dissimilar individuals.
  22. Outflow The volume of growing cells that is removed from a bioreactor during a continuous fermentation process.
  23. Ovarian follicle An external, fluid-filled portion of the ovary in which oocytes mature before ovulation.
  24. ovary (OH-vuh-ree) One of a pair of female reproductive glands in which the ova, or eggs, are formed.
  25. overdominance Where heterozygote performance is superior to that of either parental genotype.
  26. Overhang See: extension.
  27. Overlapping clones See: genomic library
  28. overlapping reading frame Start codons in different reading frames generate different polypeptides from the same DNA sequence.
  29. Overlapping reading frames Start codons in different reading frames generate different polypeptides from the same DNA sequence. (See Reading frame.)
  30. Oviduct The passage through which the ova travel from the ovary into the uterus.
  31. ovulation (ov-yoo-LA-shun) The release of an egg from an ovary during the menstrual cycle.
  32. Ovule The part of the seed plant's reproductive organs that comprises the nucellus, the embryo sac and the integuments.
  33. Ovum A female gamete.
  34. ovum pickup (Abbreviation: OPU). The non-surgical collection of ova from a female.
  35. oxidative phosphorylation The enzymatic addition of a phosphate to ADP to make ATP, coupled to electron transport from a substrate to molecular oxygen.
  36. oxygen-electrode-based sensor Sensor in which an oxygen electrode, which measures the amount of oxygen in a solution, is coated with a biological material such as an enzyme which…
  37. p Denotes the shorter of the two chromosome arms, e.g. human 14p is the short arm of human chromosome 14.
  38. P element A Drosophila transposon.
  39. P-site Abbreviation for peptidyl-tRNA binding site.
  40. P1, P2 Generational symbols for the two parents of a given individual.
  41. P1-derived artificial chromosome (PAC) One type of vector used to clone DNA fragments (100- to 300-kb insert size; average, 150 kb) in Escherichia coli cells.
  42. p53 A gene which normally regulates the cell cycle and protects the cell from damage to its genome.
  43. p53 gene A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.
  44. pachynema A mid-prophase stage in the first meiotic division, between zygonema and diplonema. Chromosomes appear as long, paired threads.
  45. pachytene (adj.) See: pachynema.
  46. packaging cell line A cell line designed to produce viral particles that do not contain nucleic acid.
  47. packed cell volume (Abbreviation: PCV). The proportion of a cell culture volume that is occupied by cells.
  48. PAGE A single image of the equivalent of one piece of paper. One or several pages make up a Document.
  49. pair-rule gene A gene that influences the formation of body segments in Drosophila.
  50. pairing The pairing of homologous chromosomes during the prophase of the first meiotic division.
  51. palaeontology The study of the fossil record of past geological periods and of the phylogenetic relationships between extinct and contemporary plant and animal species.
  52. Paleontology The study of the fossil record of past geo- logical periods and of the phylogenetic relationships between ancient and contemporary plant and animal…
  53. Palindrome See Palindromic sequence.
  54. Palindromic sequence A DNA locus whose 5'-to-3' sequence is identical on each DNA strand. The sequence is the same when one strand is read left to right and the other strand…
  55. palisade parenchyma Elongated cells found just beneath the upper epidermis of leaves, typically rich in chloroplasts.
  56. pAMP Ampicillin-resistant plasmid developed for this laboratory course. (See Plasmid.)
  57. pancreas A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones…
  58. Pancreatic beta cells Cells of the pancreas (located in pancreatic islets, or islets of Langerhans) that produce insulin.
  59. Pancreatic polypeptide An endocrine protein produced by islet cells of the pancreas.
  60. panicle An inflorescence, the main axis of which is branched; the branches bear loose racemose flower clusters.
  61. panicle culture Aseptic culture of immature panicle explants to induce microspore germination and development.
  62. panmictic population A population in which mating occurs at random.
  63. panmixis Random mating in a population.
  64. paper raft technique See: nurse culture.
  65. PAR Performance and Accountability Report -- see Annual Reports for more
  66. par gene One of a class of genes required for faithful plasmid segregation at cell division.
  67. paracentric inversion A chromosomal rearrangement in which a segment of chromosome, excluding the centromere, is rotated.
  68. Paracrine factors Cytokines or hormones that act on cells or tissues within an extremely limited area.
  69. paraffin [wax] A translucent, white, solid hydrocarbon with a low melting point. One use is as an embedding medium to support tissue for sectioning for light microscopy…
  70. Parafilmä A stretchable film based on paraffin wax; used to seal tubes and Petri dishes. Parafilmä is a proprietary name which is incorrectly applied colloquially…
  71. parahormone A substance with hormone-like properties that is not a secretory product (e.g. ethylene; carbon dioxide).
  72. parallel evolution The development of different organisms along similar evolutionary paths due to similar selection pressures acting on them.
  73. paralogous Homologous genes/gene products that have duplicated and evolved divergently within a species. e.g. beta- and gamma-globulin genes
  74. parameter A value or measurement that varies with circumstances, and is used as a reference to quantify a situation or a process.
  75. parasexual cycle A sexual cycle involving changes in chromosome number but differing in time and place from the usual sexual cycle; occurring in those fungi in which the…
  76. parasexual hybridization See: somatic hybridization.
  77. parasite An animal or plant that gets nutrients by living on or in an organism of another species.
  78. Parasitism The closee association of two or more dissimilar organisms where the association is harmful to at least one. See Commensalism, Parasitism, Symbiosis.
  79. parasporal crystal Tightly packaged insect pro-toxin molecules that are produced by strains of Bacillus thuringiensis during the formation of resting spores.
  80. paratope Synonym for antibody binding site.
  81. parenchyma (pah-REN-kih-ma) The essential or functional elements of an organ.
  82. parenchymatous (adj.) See: parenchyma.
  83. Parkinson disease (PAR-kin-sun dih-ZEEZ) A progressive disorder of the nervous system marked by muscle tremors, muscle rigidity, decreased mobility, stooped posture, slow…
  84. Parkinson's disease A common progressive neurological disorder that results from degeneration of nerve cells in a region of the brain that controls movement.
  85. parthenocarpy The development of fruit without fertilization.
  86. Parthenogenesis Production of an embryo from an unfertilized egg.
  87. partial digest Incomplete reaction of a restriction enzyme with DNA, such that only a proportion of the target sites are cleaved.
  88. particle radiation High energy nuclear emissions, used as physical agents of mutagenesis. Three major types typically used: alpha (☐) (positively charged), beta (☐)…
  89. parts per million (Abbreviation: ppm). Unit of concentration: 1ppm = 1mg dissolved matter per litre of solution.
  90. parturition The process of giving birth.
  91. Passage The transfer or transplantation of cells from one culture medium to another.
  92. passage number The number of times cells in culture have been sub-cultured.
  93. passage time Time interval between successive sub-cultures.
  94. passive immunity 1. Natural acquisition of antibodies by the foetus or neonate (newborn) from the mother. 2.
  95. pat gene A gene obtained from Streptomyces sp. encoding resistance to glufosinate-ammonium containing herbicides. (These inhibit plant synthesis of glutamine).
  96. patent A grant to an inventor of the right to exclude others, for a limited time, from making, using, or selling his invention in the United States.
  97. paternal Pertaining to the father.
  98. Pathogen Bacteria, viruses, parasites or fungi can cause disease.
  99. pathogen-free Uncontaminated with pathogen.
  100. pathogenesis related protein (Abbreviation: PR protein ). One of a group of proteins that are characteristically highly expressed as part of a plant's response to pathogen attack.