Biotechnology and Genetics terms starting with O

89 terms

1. Occupational Safety and Health Act See Occupational Safety and Health Administration.
2. Occupational Safety and Health Administration (OSHA) One of the U.S. agencies responsible for regulation of biotechnology. The major law under which the agency has regulatory powers is the Occupational…
3. ochre stop codon See: stop codon.
4. octoploid . An organism, or a tissue whose cells contain eight haploid sets of chromosomes.
5. oestrogen The generic term for a group of female sex hormones which control the development of sexual characteristics and control oestrus.
6. oestrous (adj.) See: oestrus.
7. oestrous cycle The cycle of reproductive activity shown by most sexually mature non-pregnant female mammals. AlteRNA tive spelling: estrous.
8. oestrus In female mammals, the period of sexual excitement and acceptance of the male. Synonyms: rut, heat. AlteRNA tive spelling: estrus (adj.: estrous).
9. offset You offset an options or futures position by taking a second position in a contract with identical terms, buying if you sold initially or selling if you…
10. offshoot Short, usually horizontal, stem produced near the crown of a plant.
11. offspring New individuals resulting from sexual or asexual reproduction. Synonym: progeny.
12. Okazaki fragment Replicated DNA fragments formed on the lagging strand in DNA synthesis from a double-stranded template.
13. OLA Abbreviation for oligonucleotide ligation assay.
14. Olfactory bulb A part of the brain involved in detecting and discriminating among different smells.
15. Oligo Oligonucleotide, short sequence of single-stranded DNA or RNA. Oligos are often used as probes for detecting complementary DNA or RNA because they bind…
16. Oligodendrocyte (AH-lih-goh-DEN-droh-site) A cell that forms the myelin sheath (a layer that covers and protects nerve cells) in the brain and spinal cord.
17. Oligogenic A phenotypic trait produced by two or more genes working together. See also: polygenic disorder
18. oligomer A molecule formed by the covalent joining of a small (undefined) number of monomers . See: polymer.
19. Oligonucleotide A DNA polymer composed of only a few nucleotides. (See Nucleotide.)
20. oligonucleotide ligation assay (Abbreviation: OLA). A diagnostic technique for determining the presence or absence of a single nucleotide polymorphism within a sequence, often…
21. oligonucleotide-directed mutagenesis See: site-specific mutagenesis.
22. oligonucleotide-directed site-specific mutagenesis See: site-specific mutagenesis.
23. Oligopotent progenitor cells Progenitor cells that can produce more than one type of mature cell. An example is the myeloid progenitor cell which can give rise to mature blood cells…
24. oligosaccharide Carbohydrate consisting of several linked monosaccharide units.
25. onco-mouse A mouse that has been genetically modified to incorporate an oncogene, which acts as an animal model for studies of human cancer.
26. oncogene A gene that normally directs cell growth. If altered, an oncogene can promote or allow the uncontrolled growth of cancer.
27. Oncogenesis The progression of cytological, genetic, and cellular changes that culminate in a malignant tumor.
28. oncovirus A class of retroviruses that cause a cell to become cancerous. See also cell, retrovirus, cancer, gene
29. ontogeny Developmental life history of an organism.
30. Oocyte The egg mother cell; it undergoes two meiotic divisions (oogenesis ) to form the egg cell.
31. Oocytes Egg cells.
32. oogenesis The formation and growth of the egg in an animal ovary.
33. oogonium 1. A germ cell of the female animal, that gives rise to oocytes by mitotic division. 2. The female sex organ of algae and fungi.
34. oosphere The non-motile female gamete in plants and some algae.
35. oospore A spore developing from a zygote of certain algae and fungi, following the fusion of heterogametes.
36. opal stop codon See: stop codon.
37. open continuous culture A continuous culture system, in which inflow of fresh medium is balanced by outflow of a corresponding volume of spent medium plus cells.
38. Open pollination Pollination by wind, insects, or other natural mechanisms.
39. Open reading frame A long DNA sequence that is unin- terrupted by a stop codon and encodes part or all of a protein. (See Reading frame.)
40. Open reading frame (ORF) The sequence of DNA or RNA located between the start-code sequence (initiation codon) and the stop-code sequence (termination codon).
41. operational definition An operation or procedure that can be carried out to define or delimit something.
42. operator A prokaryotic regulatory element that interacts with a repressor to control the transcription of adjacent structural genes.
43. Operon A functionally integrated genetic unit for the control of gene expression in bacteria.
44. OPINE The condensation product of an amino acid with either a keto-acid or a sugar, produced by the plant host as a result of Agrobacterium infection, and used…
45. OPU Abbreviation for ovum pickup.
46. ORF Abbreviation for open reading frame.
47. organ A part of the body that performs a specific function. For example, the heart is an organ.
48. organ culture The aseptic culture of complete living organs of animals and plants outside the body in a suitable culture medium.
49. organellar gene Genes located on organelles outside the nucleus.
50. organelle (OR-guh-NEL) A small structure in a cell that is surrounded by a membrane and has a specific function.
51. Organic agriculture A concept and practice of agricultural production that focuses on production without the use of synthetic pesticides.
52. organic complex A chemically undefined compound added to nutrient media to stimulate growth, e.g. coconut milk; malt extract; yeast extract; casein hydrolysate.
53. organic evolution See: evolution.
54. organism A living thing, such as an animal, a plant, a bacterium, or a fungus.
55. organized growth The development under tissue culture conditions of organized explants (meristem tips or shoot tips, floral buds or organ primordia).
56. organized tissue Composed of normally differentiated cells.
57. organogenesis The initiation of adventitious or de novo shoots or roots from callus, meristem or suspension cultures. See: micropropagation; regeneration.
58. organoid An organ-like structure produced in culture.
59. organoleptic Having an effect on one of the organs of sense, such as taste or smell.
60. Origin of replication The nucleotide sequence at which DNA synthesis is initiated.
61. orphan gene A gene or DNA sequence whose function is not known.
62. orphan receptor A receptor for which a cellular function or ligand has yet to be identified.
63. ortet The plant from which a clone is obtained. Synonym: donor plant.
64. orthologous Homologous genes/gene products that have evolved divergently between species; many rice genes have orthologues in other cereal genomes, because of the…
65. OSHA See Occupational Safety and Health Administration.
66. osmosis Diffusion of water across a semi-permeable membrane from zones of low solute concentration to zones of higher solute concentration.
67. osmotic potential Change in the energy state of solvent brought about by dissolving a substance in the solvent - water in the biological sciences.
68. osmoticum A chemical agent (e.g. polyethylene glycol, mannitol, glucose or sucrose) employed to maintain the osmotic potential of a nutrient medium equivalent to…
69. Osteocalcin (OC) A cytokine produced by osteoblasts that promotes bone formation.
70. Osteoclast A giant multi-nuclear cell formed in the bone marrow of growing bones.
71. Osteocyte A cell from the bone tissue.
72. Osteogenesis imperfecta A large and miscellaneous group of conditions of abnormal fragility and plasticity of bone, with recurring fractures on trivial trauma.
73. Osteoprogenitor A cell-type that differentiates into a mature osteocyte.
74. outbreeding A mating system characterized by the inter-breeding of genetically unrelated or dissimilar individuals.
75. Outflow The volume of growing cells that is removed from a bioreactor during a continuous fermentation process.
76. Ovarian follicle An external, fluid-filled portion of the ovary in which oocytes mature before ovulation.
77. ovary (OH-vuh-ree) One of a pair of female reproductive glands in which the ova, or eggs, are formed.
78. overdominance Where heterozygote performance is superior to that of either parental genotype.
79. Overhang See: extension.
80. Overlapping clones See: genomic library
81. overlapping reading frame Start codons in different reading frames generate different polypeptides from the same DNA sequence.
82. Overlapping reading frames Start codons in different reading frames generate different polypeptides from the same DNA sequence. (See Reading frame.)
83. Oviduct The passage through which the ova travel from the ovary into the uterus.
84. ovulation (ov-yoo-LA-shun) The release of an egg from an ovary during the menstrual cycle.
85. Ovule The part of the seed plant's reproductive organs that comprises the nucellus, the embryo sac and the integuments.
86. Ovum A female gamete.
87. ovum pickup (Abbreviation: OPU). The non-surgical collection of ova from a female.
88. oxidative phosphorylation The enzymatic addition of a phosphate to ADP to make ATP, coupled to electron transport from a substrate to molecular oxygen.
89. 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…