Biotechnology and Genetics terms starting with P

399 terms

1. p Denotes the shorter of the two chromosome arms, e.g. human 14p is the short arm of human chromosome 14.
2. P element A Drosophila transposon.
3. P-site Abbreviation for peptidyl-tRNA binding site.
4. P1, P2 Generational symbols for the two parents of a given individual.
5. 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.
6. p53 A gene which normally regulates the cell cycle and protects the cell from damage to its genome.
7. p53 gene A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.
8. pachynema A mid-prophase stage in the first meiotic division, between zygonema and diplonema. Chromosomes appear as long, paired threads.
9. pachytene (adj.) See: pachynema.
10. packaging cell line A cell line designed to produce viral particles that do not contain nucleic acid.
11. packed cell volume (Abbreviation: PCV). The proportion of a cell culture volume that is occupied by cells.
12. PAGE A single image of the equivalent of one piece of paper. One or several pages make up a Document.
13. pair-rule gene A gene that influences the formation of body segments in Drosophila.
14. pairing The pairing of homologous chromosomes during the prophase of the first meiotic division.
15. palaeontology The study of the fossil record of past geological periods and of the phylogenetic relationships between extinct and contemporary plant and animal species.
16. Paleontology The study of the fossil record of past geo- logical periods and of the phylogenetic relationships between ancient and contemporary plant and animal…
17. Palindrome See Palindromic sequence.
18. 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…
19. palisade parenchyma Elongated cells found just beneath the upper epidermis of leaves, typically rich in chloroplasts.
20. pAMP Ampicillin-resistant plasmid developed for this laboratory course. (See Plasmid.)
21. pancreas A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones…
22. Pancreatic beta cells Cells of the pancreas (located in pancreatic islets, or islets of Langerhans) that produce insulin.
23. Pancreatic polypeptide An endocrine protein produced by islet cells of the pancreas.
24. panicle An inflorescence, the main axis of which is branched; the branches bear loose racemose flower clusters.
25. panicle culture Aseptic culture of immature panicle explants to induce microspore germination and development.
26. panmictic population A population in which mating occurs at random.
27. panmixis Random mating in a population.
28. paper raft technique See: nurse culture.
29. PAR Performance and Accountability Report -- see Annual Reports for more
30. par gene One of a class of genes required for faithful plasmid segregation at cell division.
31. paracentric inversion A chromosomal rearrangement in which a segment of chromosome, excluding the centromere, is rotated.
32. Paracrine factors Cytokines or hormones that act on cells or tissues within an extremely limited area.
33. 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…
34. 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…
35. parahormone A substance with hormone-like properties that is not a secretory product (e.g. ethylene; carbon dioxide).
36. parallel evolution The development of different organisms along similar evolutionary paths due to similar selection pressures acting on them.
37. paralogous Homologous genes/gene products that have duplicated and evolved divergently within a species. e.g. beta- and gamma-globulin genes
38. parameter A value or measurement that varies with circumstances, and is used as a reference to quantify a situation or a process.
39. 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…
40. parasexual hybridization See: somatic hybridization.
41. parasite An animal or plant that gets nutrients by living on or in an organism of another species.
42. Parasitism The closee association of two or more dissimilar organisms where the association is harmful to at least one. See Commensalism, Parasitism, Symbiosis.
43. parasporal crystal Tightly packaged insect pro-toxin molecules that are produced by strains of Bacillus thuringiensis during the formation of resting spores.
44. paratope Synonym for antibody binding site.
45. parenchyma (pah-REN-kih-ma) The essential or functional elements of an organ.
46. parenchymatous (adj.) See: parenchyma.
47. 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…
48. Parkinson's disease A common progressive neurological disorder that results from degeneration of nerve cells in a region of the brain that controls movement.
49. parthenocarpy The development of fruit without fertilization.
50. Parthenogenesis Production of an embryo from an unfertilized egg.
51. partial digest Incomplete reaction of a restriction enzyme with DNA, such that only a proportion of the target sites are cleaved.
52. particle radiation High energy nuclear emissions, used as physical agents of mutagenesis. Three major types typically used: alpha (☐) (positively charged), beta (☐)…
53. parts per million (Abbreviation: ppm). Unit of concentration: 1ppm = 1mg dissolved matter per litre of solution.
54. parturition The process of giving birth.
55. Passage The transfer or transplantation of cells from one culture medium to another.
56. passage number The number of times cells in culture have been sub-cultured.
57. passage time Time interval between successive sub-cultures.
58. passive immunity 1. Natural acquisition of antibodies by the foetus or neonate (newborn) from the mother. 2.
59. pat gene A gene obtained from Streptomyces sp. encoding resistance to glufosinate-ammonium containing herbicides. (These inhibit plant synthesis of glutamine).
60. 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.
61. paternal Pertaining to the father.
62. Pathogen Bacteria, viruses, parasites or fungi can cause disease.
63. pathogen-free Uncontaminated with pathogen.
64. 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.
65. pathotoxin Substance secreted by certain pathogens, in order to attack the host tissue. Some pathotoxins are also toxic to non-hosts, especially animals or humans.
66. pathovar Strain of a plant-attacking bacterium or fungus that can be differentiated from others by their interaction with specific s.
67. PBR Abbreviation for plant breeders' rights.
68. pBR322 A derivation of ColE1, one of the first plasmid vectors widely used. (See Plasmid.)
69. PCR A laboratory method used to make many copies of a specific DNA sequence. Also called polymerase chain reaction.
70. PCR-RFLP AlteRNA tive term for cleaved amplified polymorphic sequence.
71. PCV Abbreviation for packed cell volume.
72. pectin A group of naturally occurring complex polysaccharides, containing galacturonic acid, found in plant cell wall s, where their function is to cement cells…
73. pectinase Enzyme catalysing the hydrolysis of pectin. Used in conjunction with cellulase to solubilize plant cell walls.
74. pedicel Stalk or stem of the individual flowers of an inflorescence.
75. pedigree A record of one's ancestors, offspring, siblings, and their offspring that may be used to determine the pattern of certain genes or disease inheritance…
76. peduncle Stalk or stem of a flower that is born singly; the main stem of an inflorescence.
77. PEG Abbreviation for polyethylene glycol.
78. Penetrance The proportion of individuals in a population that express the phenotype expected from their genotype with respect to a specific gene.
79. peptidase An enzyme that catalyzes the hydrolysis of a peptide bond.
80. peptide Any compound consisting of two or more amino acids, the building blocks of proteins.
81. peptide bond The chemical bond holding amino acid residues together in peptides and proteins.
82. peptide expression library A collection of peptide molecules, produced by recombinant cells, in which the amino acid sequences are varied.
83. peptide nucleic acid (Abbreviation: PNA). A synthetic oligonucleotide analogue, in which the sugar backbone is replaced by a peptide chain, upon which the nucleoside residues…
84. peptide vaccine A short chain of amino acids that can induce antibodies against a specific infectious agent.
85. peptidyl transferase An enzyme bound tightly to the large sub-unit of the ribosome, that catalyses the formation of peptide bonds between amino acids during translation.
86. peptidyl-tRNA binding site (Abbreviation: P-site). The site on a ribosome that hosts the tRNA to which the next amino acid for the growing polypeptide chain is attached.
87. perennial A plant that flowers continuously for several years.
88. pericentric inversion A chromosomal rearrangement in which a segment of chromosome, including the centromere, is rotated.
89. periclinal The orientation of cell wall or plane of cell division parallel to the reference surface.
90. periclinal chimera 1. Genotypically or cytoplasmically different tissues arranged in concentric layers. 2.
91. pericycle Region of the plant bounded externally by the endodermis and internally by the phloem. Most roots originate from the pericycle.
92. Peripheral Blood Stem Cell Transplant (PBSCT) A method of separating and collecting stem cells from the circulating blood stream using a process called pheresis.
93. periplasm The space between the cell (cytoplasmic) membrane of a bacterium or fungus and the outer membrane or cell wall. Synonym: periplasmic space.
94. permanent wilting point (Abbreviation: PWP). The moisture content of a soil below which plants wilt to such an extent that they fail to recover even when fully watered.
95. Permeable Referring to a membrane, cell or cell system through which small molecules can diffuse.
96. persistence Ability of an organism to remain in a particular setting for a period of time after it is introduced.
97. Persistent Chemicals with a long inactivation or degradation time, such as some pesticides.
98. PERV Abbreviation for porcine endogenous retrovirus.
99. Pesticide (PES-tih-side) Any substance that is used to kill insects and other pests.
100. Pesticide resistance A genetic change in response to selection by a pesticide, resulting in the development of strains capable of surviving a dose lethal to most individuals…