Food Biotechnology — page 34 of 34

3,375 terms

Food Biotechnology terms

  1. vessel element A type of cell occurring within the xylem of flowering plants. Many are water-conducting vessels.
  2. viability The capability to live and develop normally.
  3. viability test Assay of the number or percent of living cells or plants in a population following a specific treatment.
  4. viable Capable of normal completion of life cycle.
  5. vibrio Comma-shaped bacterium.
  6. vir genes A set of genes on a Ti plasmid that prepare the T-DNA segment for transfer into a plant cell.
  7. viral coat protein A protein present in the layer surrounding the nucleic acid core of a virus.
  8. Viral oncogene A viral gene that contributes to malig- nancies in vertebrate hosts. (See Oncogene.)
  9. viral pathogen A disease-causing virus.
  10. viral vaccine Vaccine consisting of live viruses, genetically engineered to avoid causing the disease itself.
  11. virion A complete infectious virus particle.
  12. Viroid A plant pathogen that consists of a naked RNA molecule of approximately 250-350 nucleotides, whose extensive base pairing results in a nearly correct…
  13. virulence The ability of a microorganism to cause damage to its host.
  14. virulent phage A phage that destroys its host bacterium.
  15. viruliferous A vector (usually insect) organism that carries virions and spreads the virus from host to host by mechanical means.
  16. Virus (VY-rus) In medicine, a very simple microorganism that infects cells and may cause disease.
  17. virus-free Plant, animal, cell, tissue or meristem which exhibits no viral symptoms or contains no identifiable virus particles.
  18. virus-tested Description of a organism or a cell stock certified as being free of certain specified virus es following recognized procedures of virus diagnosis.
  19. vitamin A key nutrient that the body needs in small amounts to grow and stay strong. Examples are vitamins A, C, and E.
  20. Vitamins Various substances that are essential in minute quantities to the nutrition of animals and plants.
  21. vitrified Cultured tissue having leaves and sometimes stems with a glassy, transparent or wet and often swollen appearance.
  22. viviparous (adj.) See: vivipary.
  23. vivipary 1. A form of reproduction in animals in which the developing embryo obtains its nourishment directly from the mother via a placenta or by other means. 2.
  24. Vmax The maximal rate of an enzyme-catalysed reaction. Vmax is the product of Eo (the total amount of enzyme ) and Kcat (the catalytic rate constant).
  25. VNTR Abbreviation for variable number tandem repeat.
  26. volatilization The conversion of a solid or liquid into a gas or vapour.
  27. VSG See Variable surface glycoprotein.
  28. w/v Abbreviation for weight per volume. The relative proportions of solid and liquid in a solution.
  29. walking See: chromosome walking; primer walking.
  30. wall pressure Pressure that a cell wall exerts against the turgor of the cell contents. Wall pressure is equal and opposite to the turgor potential.
  31. wash-out The loss of the slower growing micro-organism when two organisms are being grown together.
  32. water potential The pressure gradient that induces the flow of water, particularly with reference to plant water uptake from the soil, comprising the net effects of…
  33. water soaked See: vitrified.
  34. water stress Occurs when plants are unable to absorb enough water to replace that lost by transpiration. Short-term water stress leads to turgor loss (wilting).
  35. wax Water-insoluble esters of long-chain acids with long-chain alcohols. Waxes form protective waterproof layers on leaves, stems, fruits, animal fur and…
  36. Weed An undesirable plant.
  37. Weediness Unwanted effects of a plant.
  38. Western blot A test for detecting the specific antibodies to HIV in a person's blood. It is commonly used to verify positive EIA tests.
  39. wet weight See: fresh weight.
  40. wetting agent A substance (usually a detergent) that improves the contact of a liquid to a solid surface by reducing its surface tension.
  41. Wild type An organism as found in nature; the organism before it is genetically engineered.
  42. wilt Drooping of stems and foliage due to loss of cell turgor. May be caused by water stress or by disease.
  43. Wilting point The moisture content of soil at which plants start to wilt, but not to the extent that they fail to recover when placed in a humid atmosphere.
  44. wobble hypothesis An explanation of how one tRNA may recognize more than one codon. The first two bases of the mRNA codon and anticodon pair properly, but the third base in…
  45. x The basic number of chromosomes in a polyploid series, monoploid/haploid = x; diploid = 2x; triploid = 3x; etc.
  46. X chromosome See: sex chromosome.
  47. X-linked The presence of a gene on the X-chromosome.
  48. X-linked disease A genetic disease caused by a mutation on the X chromosome. In X-linked recessive conditions, a normal female "carrier" passes on the mutated X chromosome…
  49. X-ray crystallography The diffraction pattern of X-rays passing through a pure crystal of a substance.
  50. xanthophyll A yellow oxygen-containing carotenoid, present in chloroplasts.
  51. xenia The immediate effect of pollen on some characters of the endosperm.
  52. xenobiotic A chemical compound that is not produced by, and often cannot be degraded by, living organisms.
  53. xenogeneic Refers to organ s, genetically engineered ("humanized") todecrease the chance of rejection, that have been grown in an animal of another species for…
  54. Xenotransplantation The transplantation of tissue or organs from one species to another species, typically from pigs to humans. Zoonoses are an important issue.
  55. xerophyte A plant very resistant to drought, typically adapted to extremely dry environments.
  56. xylem A complex tissue specialized for the conduction of water and mineral nutrients in solution.
  57. Y chromosome See: sex chromosome.
  58. YAC Abbreviation for yeast artificial chromosome.
  59. yeast A unicellular ascomycete fungus, commonly found as a contaminant in plant tissue culture.
  60. yeast artificial chromosome (Abbreviation: YAC ). A vector which can be propagated in budding yeast (Saccharamyces pombe), consisting of the minimal elements required for a…
  61. yeast episomal vector (Abbreviation: YEp). A cloning plasmid vector for the yeast Saccharomyces cerevisiae maintained as an extrachromosomal nuclear DNA molecule.
  62. yeast extract A mixture of substances from yeast. See: organic complex ..
  63. Z-DNA A region of DNA that is "flipped" into a lefthanded helix, characterized by alternating purines and pyrimidines, and which may be the target of a…
  64. zig-zag DNA See: Z-DNA.
  65. zinc finger A DNA-binding protein motif, characterized by two closely spaced cysteine and two histidine residues that serve as ligands for a single Zn2+ ion.
  66. zone of elongation The section of the young root or shoot just behind the apical meristem, in which the cells are enlarging and elongating rapidly.
  67. zoo blot Hybridization of cloned DNA from one species to DNA from a range of other organisms to determine the extent to which the cloned DNA is evolutionarily…
  68. zoo FISH Fluorescence in situ hybridization technique, probing metaphase chromosome s of one species with DNA from another species.
  69. Zoonosis A disease that naturally occurs in animals that can also occur in humans.
  70. zoospore A spore that possesses flagella and is therefore motile.
  71. zygonema Stage of meiotic prophase during which chromosome synapsis occurs.
  72. zygospore A thick-walled resistant spore developing from a zygote resulting from the fusion of gamete s in the course of isogamy.
  73. Zygote The diploid cell formed by the fusion of two haploid gamete s during fertilization in eukaryotic organisms with sexual reproduction.
  74. zygotene (adj.) See: zygonema.
  75. zymogen Inactive enzyme precursor that after secretion is chemically altered to the active form of the enzyme.

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